[PATCH v5 00/23] mtd: nand: denali: Denali NAND IP patch bomb

[PATCH v5 00/23] mtd: nand: denali: Denali NAND IP patch bomb

[Masahiro Yamada]

This patch series intends to solve various problems.

[1] The driver just retrieves the OOB area as-is
    whereas the controller uses syndrome page layout.
[2] Many NAND chip specific parameters are hard-coded in the driver.
[3] ONFi devices are not working
[4] It can not read Bad Block Marker

Outstanding changes are:
- Fix raw/oob callbacks for syndrome page layout
- Implement setup_data_interface() callback
- Fix/implement more commands for ONFi devices
- Allow to skip the driver internal bounce buffer
- Support PIO in case DMA is not supported
- Switch from ->cmdfunc over to ->cmd_ctrl

18 patches were merged at v2.
11 patches were merged at v3.
2 patches were merged at 4.
Here is the rest of the series.

v1: https://lkml.org/lkml/2016/11/26/144
v2: https://lkml.org/lkml/2017/3/22/804
v3: https://lkml.org/lkml/2017/3/30/90


Masahiro Yamada (23):
  mtd: nand: add generic helpers to check, match, maximize ECC settings
  mtd: nand: add a shorthand to generate nand_ecc_caps structure
  mtd: nand: denali: avoid hard-coding ECC step, strength, bytes
  mtd: nand: denali: remove Toshiba and Hynix specific fixup code
  mtd: nand: denali_dt: add compatible strings for UniPhier SoC variants
  mtd: nand: denali: set NAND_ECC_CUSTOM_PAGE_ACCESS
  mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()
  mtd: nand: denali: remove unneeded find_valid_banks()
  mtd: nand: denali: handle timing parameters by setup_data_interface()
  mtd: nand: denali: rework interrupt handling
  mtd: nand: denali: fix NAND_CMD_STATUS handling
  mtd: nand: denali: fix NAND_CMD_PARAM handling
  mtd: nand: denali: switch over to cmd_ctrl instead of cmdfunc
  mtd: nand: denali: fix bank reset function to detect the number of
    chips
  mtd: nand: denali: use interrupt instead of polling for bank reset
  mtd: nand: denali: propagate page to helpers via function argument
  mtd: nand: denali: merge struct nand_buf into struct denali_nand_info
  mtd: nand: denali: use flag instead of register macro for direction
  mtd: nand: denali: fix raw and oob accessors for syndrome page layout
  mtd: nand: denali: support hardware-assisted erased page detection
  mtd: nand: denali: skip driver internal bounce buffer when possible
  mtd: nand: denali: use non-managed kmalloc() for DMA buffer
  mtd: nand: denali: enable bad block table scan

 .../devicetree/bindings/mtd/denali-nand.txt        |   13 +
 drivers/mtd/nand/denali.c                          | 1686 +++++++++-----------
 drivers/mtd/nand/denali.h                          |   60 +-
 drivers/mtd/nand/denali_dt.c                       |   33 +-
 drivers/mtd/nand/denali_pci.c                      |   10 +-
 drivers/mtd/nand/nand_base.c                       |  220 +++
 include/linux/mtd/nand.h                           |   47 +
 7 files changed, 1103 insertions(+), 966 deletions(-)

-- 
2.7.4

[PATCH v5 01/23] mtd: nand: add generic helpers to check, match, maximize ECC settings

[Masahiro Yamada]

Driver are responsible for setting up ECC parameters correctly.
Those include:
  - Check if ECC parameters specified (usually by DT) are valid
  - Meet the chip's ECC requirement
  - Maximize ECC strength if NAND_ECC_MAXIMIZE flag is set

The logic can be generalized by factoring out common code.

This commit adds 3 helpers to the NAND framework:
nand_check_ecc_caps - Check if preset step_size and strength are valid
nand_match_ecc_req - Match the chip's requirement
nand_maximize_ecc - Maximize the ECC strength

To use the helpers above, a driver needs to provide:
  - Data array of supported ECC step size and strength
  - A hook that calculates ECC bytes from the combination of
    step_size and strength.

By using those helpers, code duplication among drivers will be
reduced.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5:
  - Move oobavail from struct nand_ecc_caps to function argument
  - Do not use goto label
  - Drop mtd_info from func args
  - Remove extra blank line

Changes in v4:
  - Newly added

Changes in v3: None
Changes in v2: None

 drivers/mtd/nand/nand_base.c | 220 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/nand.h     |  33 +++++++
 2 files changed, 253 insertions(+)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index bdfa903cd355..dc0db1011761 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -4509,6 +4509,226 @@ static int nand_set_ecc_soft_ops(struct mtd_info *mtd)
 	}
 }
 
+/**
+ * nand_check_ecc_caps - check the sanity of preset ECC settings
+ * @chip: nand chip info structure
+ * @caps: ECC caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * When ECC step size and strength are already set, check if they are supported
+ * by the controller and the calculated ECC bytes fit within the chip's OOB.
+ * On success, the calculated ECC bytes is set.
+ */
+int nand_check_ecc_caps(struct nand_chip *chip,
+			const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int preset_step = chip->ecc.size;
+	int preset_strength = chip->ecc.strength;
+	int nsteps, ecc_bytes;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	if (!preset_step || !preset_strength)
+		return -ENODATA;
+
+	nsteps = mtd->writesize / preset_step;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+
+		if (stepinfo->stepsize != preset_step)
+			continue;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			if (stepinfo->strengths[j] != preset_strength)
+				continue;
+
+			ecc_bytes = caps->calc_ecc_bytes(preset_step,
+							 preset_strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				return ecc_bytes;
+
+			if (ecc_bytes * nsteps > oobavail) {
+				pr_err("ECC (step, strength) = (%d, %d) does not fit in OOB",
+				       preset_step, preset_strength);
+				return -ENOSPC;
+			}
+
+			chip->ecc.bytes = ecc_bytes;
+
+			return 0;
+		}
+	}
+
+	pr_err("ECC (step, strength) = (%d, %d) not supported on this controller",
+	       preset_step, preset_strength);
+
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL_GPL(nand_check_ecc_caps);
+
+/**
+ * nand_match_ecc_req - meet the chip's requirement with least ECC bytes
+ * @chip: nand chip info structure
+ * @caps: ECC engine caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * If a chip's ECC requirement is provided, try to meet it with the least
+ * number of ECC bytes (i.e. with the largest number of OOB-free bytes).
+ * On success, the chosen ECC settings are set.
+ */
+int nand_match_ecc_req(struct nand_chip *chip,
+		       const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int req_step = chip->ecc_step_ds;
+	int req_strength = chip->ecc_strength_ds;
+	int req_corr, step_size, strength, nsteps, ecc_bytes, ecc_bytes_total;
+	int best_step, best_strength, best_ecc_bytes;
+	int best_ecc_bytes_total = INT_MAX;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	/* No information provided by the NAND chip */
+	if (!req_step || !req_strength)
+		return -ENOTSUPP;
+
+	/* number of correctable bits the chip requires in a page */
+	req_corr = mtd->writesize / req_step * req_strength;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+		step_size = stepinfo->stepsize;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			strength = stepinfo->strengths[j];
+
+			/*
+			 * If both step size and strength are smaller than the
+			 * chip's requirement, it is not easy to compare the
+			 * resulted reliability.
+			 */
+			if (step_size < req_step && strength < req_strength)
+				continue;
+
+			if (mtd->writesize % step_size)
+				continue;
+
+			nsteps = mtd->writesize / step_size;
+
+			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				continue;
+			ecc_bytes_total = ecc_bytes * nsteps;
+
+			if (ecc_bytes_total > oobavail ||
+			    strength * nsteps < req_corr)
+				continue;
+
+			/*
+			 * We assume the best is to meet the chip's requrement
+			 * with the least number of ECC bytes.
+			 */
+			if (ecc_bytes_total < best_ecc_bytes_total) {
+				best_ecc_bytes_total = ecc_bytes_total;
+				best_step = step_size;
+				best_strength = strength;
+				best_ecc_bytes = ecc_bytes;
+			}
+		}
+	}
+
+	if (best_ecc_bytes_total == INT_MAX)
+		return -ENOTSUPP;
+
+	chip->ecc.size = best_step;
+	chip->ecc.strength = best_strength;
+	chip->ecc.bytes = best_ecc_bytes;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_match_ecc_req);
+
+/**
+ * nand_maximize_ecc - choose the max ECC strength available
+ * @chip: nand chip info structure
+ * @caps: ECC engine caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * Choose the max ECC strength that is supported on the controller, and can fit
+ * within the chip's OOB.  On success, the chosen ECC settings are set.
+ */
+int nand_maximize_ecc(struct nand_chip *chip,
+		      const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int step_size, strength, nsteps, ecc_bytes, corr;
+	int best_corr = 0;
+	int best_step = 0;
+	int best_strength, best_ecc_bytes;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+		step_size = stepinfo->stepsize;
+
+		/* If chip->ecc.size is already set, respect it */
+		if (chip->ecc.size && step_size != chip->ecc.size)
+			continue;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			strength = stepinfo->strengths[j];
+
+			if (mtd->writesize % step_size)
+				continue;
+
+			nsteps = mtd->writesize / step_size;
+
+			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				continue;
+
+			if (ecc_bytes * nsteps > oobavail)
+				continue;
+
+			corr = strength * nsteps;
+
+			/*
+			 * If the number of correctable bits is the same,
+			 * bigger step_size has more reliability.
+			 */
+			if (corr > best_corr ||
+			    (corr == best_corr && step_size > best_step)) {
+				best_corr = corr;
+				best_step = step_size;
+				best_strength = strength;
+				best_ecc_bytes = ecc_bytes;
+			}
+		}
+	}
+
+	if (!best_corr)
+		return -ENOTSUPP;
+
+	chip->ecc.size = best_step;
+	chip->ecc.strength = best_strength;
+	chip->ecc.bytes = best_ecc_bytes;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_maximize_ecc);
+
 /*
  * Check if the chip configuration meet the datasheet requirements.
 
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 8f67b1581683..c28a5792eed6 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -477,6 +477,30 @@ static inline void nand_hw_control_init(struct nand_hw_control *nfc)
 }
 
 /**
+ * struct nand_ecc_step_info - ECC step information of ECC engine
+ * @stepsize: data bytes per ECC step
+ * @strengths: array of supported strengths
+ * @nstrengths: number of supported strengths
+ */
+struct nand_ecc_step_info {
+	int stepsize;
+	const int *strengths;
+	int nstrengths;
+};
+
+/**
+ * struct nand_ecc_caps - capability of ECC engine
+ * @stepinfos: array of ECC step information
+ * @nstepinfos: number of ECC step information
+ * @calc_ecc_bytes: driver's hook to calculate ECC bytes per step
+ */
+struct nand_ecc_caps {
+	const struct nand_ecc_step_info *stepinfos;
+	int nstepinfos;
+	int (*calc_ecc_bytes)(int step_size, int strength);
+};
+
+/**
  * struct nand_ecc_ctrl - Control structure for ECC
  * @mode:	ECC mode
  * @algo:	ECC algorithm
@@ -1244,6 +1268,15 @@ int nand_check_erased_ecc_chunk(void *data, int datalen,
 				void *extraoob, int extraooblen,
 				int threshold);
 
+int nand_check_ecc_caps(struct nand_chip *chip,
+			const struct nand_ecc_caps *caps, int oobavail);
+
+int nand_match_ecc_req(struct nand_chip *chip,
+		       const struct nand_ecc_caps *caps,  int oobavail);
+
+int nand_maximize_ecc(struct nand_chip *chip,
+		      const struct nand_ecc_caps *caps, int oobavail);
+
 /* Default write_oob implementation */
 int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page);
 
-- 
2.7.4

[PATCH v5 02/23] mtd: nand: add a shorthand to generate nand_ecc_caps structure

[Masahiro Yamada]

struct nand_ecc_caps was designed as flexible as possible to support
multiple stepsizes (like sunxi_nand.c).

So, we need to write multiple arrays even for the simplest case.
I guess many controllers support a single stepsize, so here is a
shorthand macro for the case.

It allows to describe like ...

NAND_ECC_CAPS_SINGLE(denali_pci_ecc_caps, denali_calc_ecc_bytes, 512, 8, 15);

... instead of

static const int denali_pci_ecc_strengths[] = {8, 15};
static const struct nand_ecc_step_info denali_pci_ecc_stepinfo = {
        .stepsize = 512,
        .strengths = denali_pci_ecc_strengths,
        .nstrengths = ARRAY_SIZE(denali_pci_ecc_strengths),
};
static const struct nand_ecc_caps denali_pci_ecc_caps = {
        .stepinfos = &denali_pci_ecc_stepinfo,
        .nstepinfos = 1,
        .calc_ecc_bytes = denali_calc_ecc_bytes,
};

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5:
  - Newly added

Changes in v4: None
Changes in v3: None
Changes in v2: None

 include/linux/mtd/nand.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index c28a5792eed6..c08954a39657 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -500,6 +500,20 @@ struct nand_ecc_caps {
 	int (*calc_ecc_bytes)(int step_size, int strength);
 };
 
+/* a shorthand to generate struct nand_ecc_caps with only one ECC stepsize */
+#define NAND_ECC_CAPS_SINGLE(__name, __calc, __step, ...)	\
+static const int __name##_strengths[] = { __VA_ARGS__ };	\
+static const struct nand_ecc_step_info __name##_stepinfo = {	\
+	.stepsize = __step,					\
+	.strengths = __name##_strengths,			\
+	.nstrengths = ARRAY_SIZE(__name##_strengths),		\
+};								\
+static const struct nand_ecc_caps __name = {			\
+	.stepinfos = &__name##_stepinfo,			\
+	.nstepinfos = 1,					\
+	.calc_ecc_bytes = __calc,				\
+}
+
 /**
  * struct nand_ecc_ctrl - Control structure for ECC
  * @mode:	ECC mode
-- 
2.7.4

[PATCH v5 03/23] mtd: nand: denali: avoid hard-coding ECC step, strength, bytes

[Masahiro Yamada]

This driver was originally written for the Intel MRST platform with
several platform-specific parameters hard-coded.

Currently, the ECC settings are hard-coded as follows:

  #define ECC_SECTOR_SIZE 512
  #define ECC_8BITS       14
  #define ECC_15BITS      26

Therefore, the driver can only support two cases.
 - ecc.size = 512, ecc.strength = 8    --> ecc.bytes = 14
 - ecc.size = 512, ecc.strength = 15   --> ecc.bytes = 26

However, these are actually customizable parameters, for example,
UniPhier platform supports the following:

 - ecc.size = 1024, ecc.strength = 8   --> ecc.bytes = 14
 - ecc.size = 1024, ecc.strength = 16  --> ecc.bytes = 28
 - ecc.size = 1024, ecc.strength = 24  --> ecc.bytes = 42

So, we need to handle the ECC parameters in a more generic manner.
Fortunately, the Denali User's Guide explains how to calculate the
ecc.bytes.  The formula is:

  ecc.bytes = 2 * CEIL(13 * ecc.strength / 16)  (for ecc.size = 512)
  ecc.bytes = 2 * CEIL(14 * ecc.strength / 16)  (for ecc.size = 1024)

For DT platforms, it would be reasonable to allow DT to specify ECC
strength by either "nand-ecc-strength" or "nand-ecc-maximize".  If
none of them is specified, the driver will try to meet the chip's ECC
requirement.

For PCI platforms, the max ECC strength is used to keep the original
behavior.

Newer versions of this IP need ecc.size and ecc.steps explicitly
set up via the following registers:
  CFG_DATA_BLOCK_SIZE       (0x6b0)
  CFG_LAST_DATA_BLOCK_SIZE  (0x6c0)
  CFG_NUM_DATA_BLOCKS       (0x6d0)

For older IP versions, write accesses to these registers are just
ignored.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Rob Herring <robh@kernel.org>
---

Changes in v5:
  - Simplify denali_calc_ecc_bytes()
  - Adjust to the udpate of generic helpers
  - export denali_calc_ecc_bytes()

Changes in v4:
  - Rewrite by using generic helpers, nand_check_caps(),
    nand_match_ecc_req(), nand_maximize_ecc().

Changes in v3:
  - Move DENALI_CAP_ define out of struct denali_nand_info
  - Use chip->ecc_step_ds as a hint to choose chip->ecc.size
    where possible

Changes in v2:
  - Change the capability prefix DENALI_CAPS_ -> DENALI_CAP_
  - Make ECC 512 cap and ECC 1024 cap independent
  - Set up three CFG_... registers

 .../devicetree/bindings/mtd/denali-nand.txt        |  7 ++
 drivers/mtd/nand/denali.c                          | 87 +++++++++++++---------
 drivers/mtd/nand/denali.h                          | 12 ++-
 drivers/mtd/nand/denali_dt.c                       |  5 ++
 drivers/mtd/nand/denali_pci.c                      |  4 +
 5 files changed, 78 insertions(+), 37 deletions(-)

diff --git a/Documentation/devicetree/bindings/mtd/denali-nand.txt b/Documentation/devicetree/bindings/mtd/denali-nand.txt
index e593bbeb2115..b7742a7363ea 100644
--- a/Documentation/devicetree/bindings/mtd/denali-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/denali-nand.txt
@@ -7,6 +7,13 @@ Required properties:
   - reg-names: Should contain the reg names "nand_data" and "denali_reg"
   - interrupts : The interrupt number.
 
+Optional properties:
+  - nand-ecc-step-size: see nand.txt for details.  If present, the value must be
+      512        for "altr,socfpga-denali-nand"
+  - nand-ecc-strength: see nand.txt for details.  Valid values are:
+      8, 15      for "altr,socfpga-denali-nand"
+  - nand-ecc-maximize: see nand.txt for details
+
 The device tree may optionally contain sub-nodes describing partitions of the
 address space. See partition.txt for more detail.
 
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 16634df2e39a..0fff11faf603 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -886,8 +886,6 @@ static int denali_hw_ecc_fixup(struct mtd_info *mtd,
 	return max_bitflips;
 }
 
-#define ECC_SECTOR_SIZE 512
-
 #define ECC_SECTOR(x)	(((x) & ECC_ERROR_ADDRESS__SECTOR_NR) >> 12)
 #define ECC_BYTE(x)	(((x) & ECC_ERROR_ADDRESS__OFFSET))
 #define ECC_CORRECTION_VALUE(x) ((x) & ERR_CORRECTION_INFO__BYTEMASK)
@@ -899,6 +897,7 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd,
 			       struct denali_nand_info *denali,
 			       unsigned long *uncor_ecc_flags, uint8_t *buf)
 {
+	unsigned int ecc_size = denali->nand.ecc.size;
 	unsigned int bitflips = 0;
 	unsigned int max_bitflips = 0;
 	uint32_t err_addr, err_cor_info;
@@ -928,9 +927,9 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd,
 			 * an erased sector.
 			 */
 			*uncor_ecc_flags |= BIT(err_sector);
-		} else if (err_byte < ECC_SECTOR_SIZE) {
+		} else if (err_byte < ecc_size) {
 			/*
-			 * If err_byte is larger than ECC_SECTOR_SIZE, means error
+			 * If err_byte is larger than ecc_size, means error
 			 * happened in OOB, so we ignore it. It's no need for
 			 * us to correct it err_device is represented the NAND
 			 * error bits are happened in if there are more than
@@ -939,7 +938,7 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd,
 			int offset;
 			unsigned int flips_in_byte;
 
-			offset = (err_sector * ECC_SECTOR_SIZE + err_byte) *
+			offset = (err_sector * ecc_size + err_byte) *
 						denali->devnum + err_device;
 
 			/* correct the ECC error */
@@ -1345,13 +1344,39 @@ static void denali_hw_init(struct denali_nand_info *denali)
 	denali_irq_init(denali);
 }
 
-/*
- * Althogh controller spec said SLC ECC is forceb to be 4bit,
- * but denali controller in MRST only support 15bit and 8bit ECC
- * correction
- */
-#define ECC_8BITS	14
-#define ECC_15BITS	26
+int denali_calc_ecc_bytes(int step_size, int strength)
+{
+	/* BCH code.  Denali requires ecc.bytes to be multiple of 2 */
+	return DIV_ROUND_UP(strength * fls(step_size * 8), 16) * 2;
+}
+EXPORT_SYMBOL(denali_calc_ecc_bytes);
+
+static int denali_ecc_setup(struct mtd_info *mtd, struct nand_chip *chip,
+			    struct denali_nand_info *denali)
+{
+	int oobavail = mtd->oobsize - denali->bbtskipbytes;
+	int ret;
+
+	/*
+	 * If .size and .strength are already set (usually by DT),
+	 * check if they are supported by this controller.
+	 */
+	if (chip->ecc.size && chip->ecc.strength)
+		return nand_check_ecc_caps(chip, denali->ecc_caps, oobavail);
+
+	/*
+	 * We want .size and .strength closest to the chip's requirement
+	 * unless NAND_ECC_MAXIMIZE is requested.
+	 */
+	if (!(chip->ecc.options & NAND_ECC_MAXIMIZE)) {
+		ret = nand_match_ecc_req(chip, denali->ecc_caps, oobavail);
+		if (!ret)
+			return 0;
+	}
+
+	/* Max ECC strength is the last thing we can do */
+	return nand_maximize_ecc(chip, denali->ecc_caps, oobavail);
+}
 
 static int denali_ooblayout_ecc(struct mtd_info *mtd, int section,
 				struct mtd_oob_region *oobregion)
@@ -1586,34 +1611,26 @@ int denali_init(struct denali_nand_info *denali)
 	/* no subpage writes on denali */
 	chip->options |= NAND_NO_SUBPAGE_WRITE;
 
-	/*
-	 * Denali Controller only support 15bit and 8bit ECC in MRST,
-	 * so just let controller do 15bit ECC for MLC and 8bit ECC for
-	 * SLC if possible.
-	 * */
-	if (!nand_is_slc(chip) &&
-			(mtd->oobsize > (denali->bbtskipbytes +
-			ECC_15BITS * (mtd->writesize /
-			ECC_SECTOR_SIZE)))) {
-		/* if MLC OOB size is large enough, use 15bit ECC*/
-		chip->ecc.strength = 15;
-		chip->ecc.bytes = ECC_15BITS;
-		iowrite32(15, denali->flash_reg + ECC_CORRECTION);
-	} else if (mtd->oobsize < (denali->bbtskipbytes +
-			ECC_8BITS * (mtd->writesize /
-			ECC_SECTOR_SIZE))) {
-		pr_err("Your NAND chip OOB is not large enough to contain 8bit ECC correction codes");
+	ret = denali_ecc_setup(mtd, chip, denali);
+	if (ret) {
+		dev_err(denali->dev, "Failed to setup ECC settings.\n");
 		goto failed_req_irq;
-	} else {
-		chip->ecc.strength = 8;
-		chip->ecc.bytes = ECC_8BITS;
-		iowrite32(8, denali->flash_reg + ECC_CORRECTION);
 	}
 
+	dev_dbg(denali->dev,
+		"chosen ECC settings: step=%d, strength=%d, bytes=%d\n",
+		chip->ecc.size, chip->ecc.strength, chip->ecc.bytes);
+
+	iowrite32(chip->ecc.strength, denali->flash_reg + ECC_CORRECTION);
+
+	iowrite32(chip->ecc.size, denali->flash_reg + CFG_DATA_BLOCK_SIZE);
+	iowrite32(chip->ecc.size, denali->flash_reg + CFG_LAST_DATA_BLOCK_SIZE);
+	/* chip->ecc.steps is set by nand_scan_tail(); not available here */
+	iowrite32(mtd->writesize / chip->ecc.size,
+		  denali->flash_reg + CFG_NUM_DATA_BLOCKS);
+
 	mtd_set_ooblayout(mtd, &denali_ooblayout_ops);
 
-	/* override the default read operations */
-	chip->ecc.size = ECC_SECTOR_SIZE;
 	chip->ecc.read_page = denali_read_page;
 	chip->ecc.read_page_raw = denali_read_page_raw;
 	chip->ecc.write_page = denali_write_page;
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 37833535a7a3..a06ed741b550 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -259,6 +259,14 @@
 #define     ECC_COR_INFO__MAX_ERRORS			GENMASK(6, 0)
 #define     ECC_COR_INFO__UNCOR_ERR			BIT(7)
 
+#define CFG_DATA_BLOCK_SIZE			0x6b0
+
+#define CFG_LAST_DATA_BLOCK_SIZE		0x6c0
+
+#define CFG_NUM_DATA_BLOCKS			0x6d0
+
+#define CFG_META_DATA_SIZE			0x6e0
+
 #define DMA_ENABLE				0x700
 #define     DMA_ENABLE__FLAG				BIT(0)
 
@@ -301,8 +309,6 @@
 #define MODE_10    0x08000000
 #define MODE_11    0x0C000000
 
-#define ECC_SECTOR_SIZE     512
-
 struct nand_buf {
 	int head;
 	int tail;
@@ -337,11 +343,13 @@ struct denali_nand_info {
 	int max_banks;
 	unsigned int revision;
 	unsigned int caps;
+	const struct nand_ecc_caps *ecc_caps;
 };
 
 #define DENALI_CAP_HW_ECC_FIXUP			BIT(0)
 #define DENALI_CAP_DMA_64BIT			BIT(1)
 
+int denali_calc_ecc_bytes(int step_size, int strength);
 extern int denali_init(struct denali_nand_info *denali);
 extern void denali_remove(struct denali_nand_info *denali);
 
diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
index b48430fe3cd4..bd1aa4cf4457 100644
--- a/drivers/mtd/nand/denali_dt.c
+++ b/drivers/mtd/nand/denali_dt.c
@@ -32,10 +32,14 @@ struct denali_dt {
 struct denali_dt_data {
 	unsigned int revision;
 	unsigned int caps;
+	const struct nand_ecc_caps *ecc_caps;
 };
 
+NAND_ECC_CAPS_SINGLE(denali_socfpga_ecc_caps, denali_calc_ecc_bytes,
+		     512, 8, 15);
 static const struct denali_dt_data denali_socfpga_data = {
 	.caps = DENALI_CAP_HW_ECC_FIXUP,
+	.ecc_caps = &denali_socfpga_ecc_caps,
 };
 
 static const struct of_device_id denali_nand_dt_ids[] = {
@@ -64,6 +68,7 @@ static int denali_dt_probe(struct platform_device *pdev)
 	if (data) {
 		denali->revision = data->revision;
 		denali->caps = data->caps;
+		denali->ecc_caps = data->ecc_caps;
 	}
 
 	denali->platform = DT;
diff --git a/drivers/mtd/nand/denali_pci.c b/drivers/mtd/nand/denali_pci.c
index ac843238b77e..37dc0934c24c 100644
--- a/drivers/mtd/nand/denali_pci.c
+++ b/drivers/mtd/nand/denali_pci.c
@@ -27,6 +27,8 @@ static const struct pci_device_id denali_pci_ids[] = {
 };
 MODULE_DEVICE_TABLE(pci, denali_pci_ids);
 
+NAND_ECC_CAPS_SINGLE(denali_pci_ecc_caps, denali_calc_ecc_bytes, 512, 8, 15);
+
 static int denali_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
 	int ret;
@@ -65,6 +67,8 @@ static int denali_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	pci_set_master(dev);
 	denali->dev = &dev->dev;
 	denali->irq = dev->irq;
+	denali->ecc_caps = &denali_pci_ecc_caps;
+	denali->nand.ecc.options |= NAND_ECC_MAXIMIZE;
 
 	ret = pci_request_regions(dev, DENALI_NAND_NAME);
 	if (ret) {
-- 
2.7.4

[PATCH v5 04/23] mtd: nand: denali: remove Toshiba and Hynix specific fixup code

[Masahiro Yamada]

The Denali IP can automatically detect device parameters such as
page size, oob size, device width, etc. and this driver currently
relies on it.  However, this hardware function is known to be
problematic.

[1] Due to a hardware bug, various misdetected cases were reported.
    That is why get_toshiba_nand_para() and get_hynix_nand_para()
    exist to fix-up the misdetected parameters.  It is not realistic
    to add a new NAND device to the *black list* every time we are
    hit by a misdetected case.  We would never be able to guarantee
    that all cases are covered.

[2] Because this feature is unreliable, it is disabled on some
    platforms.

The nand_scan_ident() detects device parameters in a more tested
way.  The hardware should not set the device parameter registers in
a different, unreliable way.  Instead, set the parameters from the
nand_scan_ident() back to the registers.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

 drivers/mtd/nand/denali.c | 40 ++++++----------------------------------
 1 file changed, 6 insertions(+), 34 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 0fff11faf603..991924b9ae2c 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -337,36 +337,6 @@ static void get_samsung_nand_para(struct denali_nand_info *denali,
 	}
 }
 
-static void get_toshiba_nand_para(struct denali_nand_info *denali)
-{
-	/*
-	 * Workaround to fix a controller bug which reports a wrong
-	 * spare area size for some kind of Toshiba NAND device
-	 */
-	if ((ioread32(denali->flash_reg + DEVICE_MAIN_AREA_SIZE) == 4096) &&
-		(ioread32(denali->flash_reg + DEVICE_SPARE_AREA_SIZE) == 64))
-		iowrite32(216, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
-}
-
-static void get_hynix_nand_para(struct denali_nand_info *denali,
-							uint8_t device_id)
-{
-	switch (device_id) {
-	case 0xD5: /* Hynix H27UAG8T2A, H27UBG8U5A or H27UCG8VFA */
-	case 0xD7: /* Hynix H27UDG8VEM, H27UCG8UDM or H27UCG8V5A */
-		iowrite32(128, denali->flash_reg + PAGES_PER_BLOCK);
-		iowrite32(4096, denali->flash_reg + DEVICE_MAIN_AREA_SIZE);
-		iowrite32(224, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
-		iowrite32(0, denali->flash_reg + DEVICE_WIDTH);
-		break;
-	default:
-		dev_warn(denali->dev,
-			 "Unknown Hynix NAND (Device ID: 0x%x).\n"
-			 "Will use default parameter values instead.\n",
-			 device_id);
-	}
-}
-
 /*
  * determines how many NAND chips are connected to the controller. Note for
  * Intel CE4100 devices we don't support more than one device.
@@ -453,10 +423,6 @@ static uint16_t denali_nand_timing_set(struct denali_nand_info *denali)
 			return FAIL;
 	} else if (maf_id == 0xEC) { /* Samsung NAND */
 		get_samsung_nand_para(denali, device_id);
-	} else if (maf_id == 0x98) { /* Toshiba NAND */
-		get_toshiba_nand_para(denali);
-	} else if (maf_id == 0xAD) { /* Hynix NAND */
-		get_hynix_nand_para(denali, device_id);
 	}
 
 	dev_info(denali->dev,
@@ -1622,6 +1588,12 @@ int denali_init(struct denali_nand_info *denali)
 		chip->ecc.size, chip->ecc.strength, chip->ecc.bytes);
 
 	iowrite32(chip->ecc.strength, denali->flash_reg + ECC_CORRECTION);
+	iowrite32(mtd->erasesize / mtd->writesize,
+		  denali->flash_reg + PAGES_PER_BLOCK);
+	iowrite32(chip->options & NAND_BUSWIDTH_16 ? 1 : 0,
+		  denali->flash_reg + DEVICE_WIDTH);
+	iowrite32(mtd->writesize, denali->flash_reg + DEVICE_MAIN_AREA_SIZE);
+	iowrite32(mtd->oobsize, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
 
 	iowrite32(chip->ecc.size, denali->flash_reg + CFG_DATA_BLOCK_SIZE);
 	iowrite32(chip->ecc.size, denali->flash_reg + CFG_LAST_DATA_BLOCK_SIZE);
-- 
2.7.4

[PATCH v5 05/23] mtd: nand: denali_dt: add compatible strings for UniPhier SoC variants

[Masahiro Yamada]

Add two compatible strings for UniPhier SoC family.

"socionext,uniphier-denali-nand-v5a" is used on UniPhier sLD3, LD4,
Pro4, sLD8.

"socionext,uniphier-denali-nand-v5b" is used on UniPhier Pro5, PXs2,
LD6b, LD11, LD20.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5:
  - Adjust to the update of generic helpers

Changes in v4:
  - Adjusted to generic helpers for ECC engine caps

Changes in v3: None
Changes in v2:
  - Change the compatible strings
  - Fix the ecc_strength_capability
  - Override revision number for the newer one

 .../devicetree/bindings/mtd/denali-nand.txt        |  6 ++++++
 drivers/mtd/nand/denali_dt.c                       | 25 ++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/denali-nand.txt b/Documentation/devicetree/bindings/mtd/denali-nand.txt
index b7742a7363ea..504291d2e5c2 100644
--- a/Documentation/devicetree/bindings/mtd/denali-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/denali-nand.txt
@@ -3,6 +3,8 @@
 Required properties:
   - compatible : should be one of the following:
       "altr,socfpga-denali-nand"            - for Altera SOCFPGA
+      "socionext,uniphier-denali-nand-v5a"  - for Socionext UniPhier (v5a)
+      "socionext,uniphier-denali-nand-v5b"  - for Socionext UniPhier (v5b)
   - reg : should contain registers location and length for data and reg.
   - reg-names: Should contain the reg names "nand_data" and "denali_reg"
   - interrupts : The interrupt number.
@@ -10,8 +12,12 @@ Required properties:
 Optional properties:
   - nand-ecc-step-size: see nand.txt for details.  If present, the value must be
       512        for "altr,socfpga-denali-nand"
+      1024       for "socionext,uniphier-denali-nand-v5a"
+      1024       for "socionext,uniphier-denali-nand-v5b"
   - nand-ecc-strength: see nand.txt for details.  Valid values are:
       8, 15      for "altr,socfpga-denali-nand"
+      8, 16, 24  for "socionext,uniphier-denali-nand-v5a"
+      8, 16      for "socionext,uniphier-denali-nand-v5b"
   - nand-ecc-maximize: see nand.txt for details
 
 The device tree may optionally contain sub-nodes describing partitions of the
diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
index bd1aa4cf4457..be598230c108 100644
--- a/drivers/mtd/nand/denali_dt.c
+++ b/drivers/mtd/nand/denali_dt.c
@@ -42,11 +42,36 @@ static const struct denali_dt_data denali_socfpga_data = {
 	.ecc_caps = &denali_socfpga_ecc_caps,
 };
 
+NAND_ECC_CAPS_SINGLE(denali_uniphier_v5a_ecc_caps, denali_calc_ecc_bytes,
+		     1024, 8, 16, 24);
+static const struct denali_dt_data denali_uniphier_v5a_data = {
+	.caps = DENALI_CAP_HW_ECC_FIXUP |
+		DENALI_CAP_DMA_64BIT,
+	.ecc_caps = &denali_uniphier_v5a_ecc_caps,
+};
+
+NAND_ECC_CAPS_SINGLE(denali_uniphier_v5b_ecc_caps, denali_calc_ecc_bytes,
+		     1024, 8, 16);
+static const struct denali_dt_data denali_uniphier_v5b_data = {
+	.revision = 0x0501,
+	.caps = DENALI_CAP_HW_ECC_FIXUP |
+		DENALI_CAP_DMA_64BIT,
+	.ecc_caps = &denali_uniphier_v5b_ecc_caps,
+};
+
 static const struct of_device_id denali_nand_dt_ids[] = {
 	{
 		.compatible = "altr,socfpga-denali-nand",
 		.data = &denali_socfpga_data,
 	},
+	{
+		.compatible = "socionext,uniphier-denali-nand-v5a",
+		.data = &denali_uniphier_v5a_data,
+	},
+	{
+		.compatible = "socionext,uniphier-denali-nand-v5b",
+		.data = &denali_uniphier_v5b_data,
+	},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, denali_nand_dt_ids);
-- 
2.7.4

[PATCH v5 06/23] mtd: nand: denali: set NAND_ECC_CUSTOM_PAGE_ACCESS

[Masahiro Yamada]

The denali_cmdfunc() actually does nothing valuable for
NAND_CMD_{PAGEPROG,READ0,SEQIN}.

For NAND_CMD_{READ0,SEQIN}, it copies "page" to "denali->page", then
denali_read_page() and denali_read_page_raw() compare them to check
if the NAND framework called the callbacks in correct order.
(Inconsistently, this check is missing from the denali_write_page()
and denali_write_page_raw().)

The framework is widely tested by many drivers, so this kind of
sanity check is unneeded.  The Denali controller is equipped with
high level interface for read/write, so let's skip unneeded call
of cmdfunc().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 991924b9ae2c..1897fe238290 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -998,7 +998,7 @@ static void denali_setup_dma(struct denali_nand_info *denali, int op)
  * configuration details.
  */
 static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
-			const uint8_t *buf, bool raw_xfer)
+			const uint8_t *buf, int page, bool raw_xfer)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
 	dma_addr_t addr = denali->buf.dma_buf;
@@ -1006,6 +1006,8 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	uint32_t irq_status;
 	uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
 
+	denali->page = page;
+
 	/*
 	 * if it is a raw xfer, we want to disable ecc and send the spare area.
 	 * !raw_xfer - enable ecc
@@ -1059,7 +1061,7 @@ static int denali_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	 * for regular page writes, we let HW handle all the ECC
 	 * data written to the device.
 	 */
-	return write_page(mtd, chip, buf, false);
+	return write_page(mtd, chip, buf, page, false);
 }
 
 /*
@@ -1075,7 +1077,7 @@ static int denali_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	 * for raw page writes, we want to disable ECC and simply write
 	 * whatever data is in the buffer.
 	 */
-	return write_page(mtd, chip, buf, true);
+	return write_page(mtd, chip, buf, page, true);
 }
 
 static int denali_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
@@ -1105,12 +1107,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 	unsigned long uncor_ecc_flags = 0;
 	int stat = 0;
 
-	if (page != denali->page) {
-		dev_err(denali->dev,
-			"IN %s: page %d is not equal to denali->page %d",
-			__func__, page, denali->page);
-		BUG();
-	}
+	denali->page = page;
 
 	setup_ecc_for_xfer(denali, true, false);
 
@@ -1154,12 +1151,7 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	size_t size = mtd->writesize + mtd->oobsize;
 	uint32_t irq_mask = INTR__DMA_CMD_COMP;
 
-	if (page != denali->page) {
-		dev_err(denali->dev,
-			"IN %s: page %d is not equal to denali->page %d",
-			__func__, page, denali->page);
-		BUG();
-	}
+	denali->page = page;
 
 	setup_ecc_for_xfer(denali, false, true);
 	denali_enable_dma(denali, true);
@@ -1238,8 +1230,6 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
 	int i;
 
 	switch (cmd) {
-	case NAND_CMD_PAGEPROG:
-		break;
 	case NAND_CMD_STATUS:
 		read_status(denali);
 		break;
@@ -1259,10 +1249,6 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
 			write_byte_to_buf(denali, id);
 		}
 		break;
-	case NAND_CMD_READ0:
-	case NAND_CMD_SEQIN:
-		denali->page = page;
-		break;
 	case NAND_CMD_RESET:
 		reset_bank(denali);
 		break;
@@ -1603,6 +1589,7 @@ int denali_init(struct denali_nand_info *denali)
 
 	mtd_set_ooblayout(mtd, &denali_ooblayout_ops);
 
+	chip->ecc.options |= NAND_ECC_CUSTOM_PAGE_ACCESS;
 	chip->ecc.read_page = denali_read_page;
 	chip->ecc.read_page_raw = denali_read_page_raw;
 	chip->ecc.write_page = denali_write_page;
-- 
2.7.4

[PATCH v5 07/23] mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()

[Masahiro Yamada]

Currently, the error handling of denali_write_page(_raw) is a bit
complicated.  If the program command fails, NAND_STATUS_FAIL is set
to the driver internal denali->status, then read out later by
denali_waitfunc().

We can avoid it by exploiting the nand_write_page() implementation.
If chip->ecc.write_page(_raw) returns negative code (i.e. -EIO), it
errors out immediately.  This gives the same result as returning
NAND_STATUS_FAIL from chip->waitfunc.  In either way, -EIO is
returned to the upper MTD layer.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 12 ++++--------
 drivers/mtd/nand/denali.h |  1 -
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 1897fe238290..22acfc34b546 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -1005,6 +1005,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	size_t size = mtd->writesize + mtd->oobsize;
 	uint32_t irq_status;
 	uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
+	int ret = 0;
 
 	denali->page = page;
 
@@ -1038,13 +1039,13 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	if (irq_status == 0) {
 		dev_err(denali->dev, "timeout on write_page (type = %d)\n",
 			raw_xfer);
-		denali->status = NAND_STATUS_FAIL;
+		ret = -EIO;
 	}
 
 	denali_enable_dma(denali, false);
 	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_TO_DEVICE);
 
-	return 0;
+	return ret;
 }
 
 /* NAND core entry points */
@@ -1196,12 +1197,7 @@ static void denali_select_chip(struct mtd_info *mtd, int chip)
 
 static int denali_waitfunc(struct mtd_info *mtd, struct nand_chip *chip)
 {
-	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	int status = denali->status;
-
-	denali->status = 0;
-
-	return status;
+	return 0;
 }
 
 static int denali_erase(struct mtd_info *mtd, int page)
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index a06ed741b550..352d8328b94a 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -323,7 +323,6 @@ struct nand_buf {
 struct denali_nand_info {
 	struct nand_chip nand;
 	int flash_bank; /* currently selected chip */
-	int status;
 	int platform;
 	struct nand_buf buf;
 	struct device *dev;
-- 
2.7.4

[PATCH v5 08/23] mtd: nand: denali: remove unneeded find_valid_banks()

[Masahiro Yamada]

The function find_valid_banks() issues the Read ID (0x90) command,
then compares the first byte (Manufacturer ID) of each bank with
the one of bank0.

This is equivalent to what nand_scan_ident() does.  The number of
chips is detected there, so this is unneeded.

What is worse for find_valid_banks() is that, if multiple chips are
connected to INTEL_CE4100 platform, it crashes the kernel by BUG().
This is what we should avoid.  This function is just harmful and
unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 47 -----------------------------------------------
 drivers/mtd/nand/denali.h |  1 -
 2 files changed, 48 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 22acfc34b546..f090486cab66 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -338,51 +338,6 @@ static void get_samsung_nand_para(struct denali_nand_info *denali,
 }
 
 /*
- * determines how many NAND chips are connected to the controller. Note for
- * Intel CE4100 devices we don't support more than one device.
- */
-static void find_valid_banks(struct denali_nand_info *denali)
-{
-	uint32_t id[denali->max_banks];
-	int i;
-
-	denali->total_used_banks = 1;
-	for (i = 0; i < denali->max_banks; i++) {
-		index_addr(denali, MODE_11 | (i << 24) | 0, 0x90);
-		index_addr(denali, MODE_11 | (i << 24) | 1, 0);
-		index_addr_read_data(denali, MODE_11 | (i << 24) | 2, &id[i]);
-
-		dev_dbg(denali->dev,
-			"Return 1st ID for bank[%d]: %x\n", i, id[i]);
-
-		if (i == 0) {
-			if (!(id[i] & 0x0ff))
-				break; /* WTF? */
-		} else {
-			if ((id[i] & 0x0ff) == (id[0] & 0x0ff))
-				denali->total_used_banks++;
-			else
-				break;
-		}
-	}
-
-	if (denali->platform == INTEL_CE4100) {
-		/*
-		 * Platform limitations of the CE4100 device limit
-		 * users to a single chip solution for NAND.
-		 * Multichip support is not enabled.
-		 */
-		if (denali->total_used_banks != 1) {
-			dev_err(denali->dev,
-				"Sorry, Intel CE4100 only supports a single NAND device.\n");
-			BUG();
-		}
-	}
-	dev_dbg(denali->dev,
-		"denali->total_used_banks: %d\n", denali->total_used_banks);
-}
-
-/*
  * Use the configuration feature register to determine the maximum number of
  * banks that the hardware supports.
  */
@@ -439,8 +394,6 @@ static uint16_t denali_nand_timing_set(struct denali_nand_info *denali)
 			ioread32(denali->flash_reg + RDWR_EN_HI_CNT),
 			ioread32(denali->flash_reg + CS_SETUP_CNT));
 
-	find_valid_banks(denali);
-
 	/*
 	 * If the user specified to override the default timings
 	 * with a specific ONFI mode, we apply those changes here.
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 352d8328b94a..0e4a8965f6f1 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -326,7 +326,6 @@ struct denali_nand_info {
 	int platform;
 	struct nand_buf buf;
 	struct device *dev;
-	int total_used_banks;
 	int page;
 	void __iomem *flash_reg;	/* Register Interface */
 	void __iomem *flash_mem;	/* Host Data/Command Interface */
-- 
2.7.4

[PATCH v5 09/23] mtd: nand: denali: handle timing parameters by setup_data_interface()

[Masahiro Yamada]

Handling timing parameters in a driver's own way should be avoided
because it duplicates efforts of drivers/mtd/nand/nand_timings.c
Besides, this driver hard-codes Intel specific parameters such as
CLK_X=5, CLK_MULTI=4.  Taking a certain device (Samsung K9WAG08U1A)
into account by get_samsung_nand_para() is weird as well.

Now, the core framework provides .setup_data_interface() hook, which
handles timing parameters in a generic manner.

While I am working on this, I found even more issues in the current
code, so fixed the following as well:

- In recent IP versions, WE_2_RE and TWHR2 share the same register.
  Likewise for ADDR_2_DATA and TCWAW, CS_SETUP_CNT and TWB.  When
  updating one, the other must be masked.  Otherwise, the other will
  be set to 0, then timing settings will be broken.

- The recent IP release expanded the ADDR_2_DATA to 7-bit wide.
  This register is related to tADL.  As commit 74a332e78e8f ("mtd:
  nand: timings: Fix tADL_min for ONFI 4.0 chips") addressed, the
  ONFi 4.0 increased the minimum of tADL to 400 nsec.  This may not
  fit in the 6-bit ADDR_2_DATA in older versions.  Check the IP
  revision and handle this correctly, otherwise the register value
  would wrap around.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c     | 351 +++++++++++++++---------------------------
 drivers/mtd/nand/denali.h     |  26 ++--
 drivers/mtd/nand/denali_dt.c  |   3 +-
 drivers/mtd/nand/denali_pci.c |   6 +-
 4 files changed, 142 insertions(+), 244 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index f090486cab66..8ad1e96f6d03 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -28,17 +28,6 @@
 
 MODULE_LICENSE("GPL");
 
-/*
- * We define a module parameter that allows the user to override
- * the hardware and decide what timing mode should be used.
- */
-#define NAND_DEFAULT_TIMINGS	-1
-
-static int onfi_timing_mode = NAND_DEFAULT_TIMINGS;
-module_param(onfi_timing_mode, int, S_IRUGO);
-MODULE_PARM_DESC(onfi_timing_mode,
-	   "Overrides default ONFI setting. -1 indicates use default timings");
-
 #define DENALI_NAND_NAME    "denali-nand"
 
 /*
@@ -63,12 +52,6 @@ MODULE_PARM_DESC(onfi_timing_mode,
 #define CHIP_SELECT_INVALID	-1
 
 /*
- * This macro divides two integers and rounds fractional values up
- * to the nearest integer value.
- */
-#define CEIL_DIV(X, Y) (((X)%(Y)) ? ((X)/(Y)+1) : ((X)/(Y)))
-
-/*
  * this macro allows us to convert from an MTD structure to our own
  * device context (denali) structure.
  */
@@ -103,6 +86,14 @@ static void denali_irq_enable(struct denali_nand_info *denali,
 static uint32_t read_interrupt_status(struct denali_nand_info *denali);
 
 /*
+ * The bus interface clock, clk_x, is phase aligned with the core clock.  The
+ * clk_x is an integral multiple N of the core clk.  The value N is configured
+ * at IP delivery time, and its available value is 4, 5, or 6.  We need to align
+ * to the largest value to make it work with any possible configuration.
+ */
+#define DENALI_CLK_X_MULT	6
+
+/*
  * Certain operations for the denali NAND controller use an indexed mode to
  * read/write data. The operation is performed by writing the address value
  * of the command to the device memory followed by the data. This function
@@ -196,148 +187,6 @@ static uint16_t denali_nand_reset(struct denali_nand_info *denali)
 }
 
 /*
- * this routine calculates the ONFI timing values for a given mode and
- * programs the clocking register accordingly. The mode is determined by
- * the get_onfi_nand_para routine.
- */
-static void nand_onfi_timing_set(struct denali_nand_info *denali,
-								uint16_t mode)
-{
-	uint16_t Trea[6] = {40, 30, 25, 20, 20, 16};
-	uint16_t Trp[6] = {50, 25, 17, 15, 12, 10};
-	uint16_t Treh[6] = {30, 15, 15, 10, 10, 7};
-	uint16_t Trc[6] = {100, 50, 35, 30, 25, 20};
-	uint16_t Trhoh[6] = {0, 15, 15, 15, 15, 15};
-	uint16_t Trloh[6] = {0, 0, 0, 0, 5, 5};
-	uint16_t Tcea[6] = {100, 45, 30, 25, 25, 25};
-	uint16_t Tadl[6] = {200, 100, 100, 100, 70, 70};
-	uint16_t Trhw[6] = {200, 100, 100, 100, 100, 100};
-	uint16_t Trhz[6] = {200, 100, 100, 100, 100, 100};
-	uint16_t Twhr[6] = {120, 80, 80, 60, 60, 60};
-	uint16_t Tcs[6] = {70, 35, 25, 25, 20, 15};
-
-	uint16_t data_invalid_rhoh, data_invalid_rloh, data_invalid;
-	uint16_t dv_window = 0;
-	uint16_t en_lo, en_hi;
-	uint16_t acc_clks;
-	uint16_t addr_2_data, re_2_we, re_2_re, we_2_re, cs_cnt;
-
-	en_lo = CEIL_DIV(Trp[mode], CLK_X);
-	en_hi = CEIL_DIV(Treh[mode], CLK_X);
-#if ONFI_BLOOM_TIME
-	if ((en_hi * CLK_X) < (Treh[mode] + 2))
-		en_hi++;
-#endif
-
-	if ((en_lo + en_hi) * CLK_X < Trc[mode])
-		en_lo += CEIL_DIV((Trc[mode] - (en_lo + en_hi) * CLK_X), CLK_X);
-
-	if ((en_lo + en_hi) < CLK_MULTI)
-		en_lo += CLK_MULTI - en_lo - en_hi;
-
-	while (dv_window < 8) {
-		data_invalid_rhoh = en_lo * CLK_X + Trhoh[mode];
-
-		data_invalid_rloh = (en_lo + en_hi) * CLK_X + Trloh[mode];
-
-		data_invalid = data_invalid_rhoh < data_invalid_rloh ?
-					data_invalid_rhoh : data_invalid_rloh;
-
-		dv_window = data_invalid - Trea[mode];
-
-		if (dv_window < 8)
-			en_lo++;
-	}
-
-	acc_clks = CEIL_DIV(Trea[mode], CLK_X);
-
-	while (acc_clks * CLK_X - Trea[mode] < 3)
-		acc_clks++;
-
-	if (data_invalid - acc_clks * CLK_X < 2)
-		dev_warn(denali->dev, "%s, Line %d: Warning!\n",
-			 __FILE__, __LINE__);
-
-	addr_2_data = CEIL_DIV(Tadl[mode], CLK_X);
-	re_2_we = CEIL_DIV(Trhw[mode], CLK_X);
-	re_2_re = CEIL_DIV(Trhz[mode], CLK_X);
-	we_2_re = CEIL_DIV(Twhr[mode], CLK_X);
-	cs_cnt = CEIL_DIV((Tcs[mode] - Trp[mode]), CLK_X);
-	if (cs_cnt == 0)
-		cs_cnt = 1;
-
-	if (Tcea[mode]) {
-		while (cs_cnt * CLK_X + Trea[mode] < Tcea[mode])
-			cs_cnt++;
-	}
-
-#if MODE5_WORKAROUND
-	if (mode == 5)
-		acc_clks = 5;
-#endif
-
-	/* Sighting 3462430: Temporary hack for MT29F128G08CJABAWP:B */
-	if (ioread32(denali->flash_reg + MANUFACTURER_ID) == 0 &&
-		ioread32(denali->flash_reg + DEVICE_ID) == 0x88)
-		acc_clks = 6;
-
-	iowrite32(acc_clks, denali->flash_reg + ACC_CLKS);
-	iowrite32(re_2_we, denali->flash_reg + RE_2_WE);
-	iowrite32(re_2_re, denali->flash_reg + RE_2_RE);
-	iowrite32(we_2_re, denali->flash_reg + WE_2_RE);
-	iowrite32(addr_2_data, denali->flash_reg + ADDR_2_DATA);
-	iowrite32(en_lo, denali->flash_reg + RDWR_EN_LO_CNT);
-	iowrite32(en_hi, denali->flash_reg + RDWR_EN_HI_CNT);
-	iowrite32(cs_cnt, denali->flash_reg + CS_SETUP_CNT);
-}
-
-/* queries the NAND device to see what ONFI modes it supports. */
-static uint16_t get_onfi_nand_para(struct denali_nand_info *denali)
-{
-	int i;
-
-	/*
-	 * we needn't to do a reset here because driver has already
-	 * reset all the banks before
-	 */
-	if (!(ioread32(denali->flash_reg + ONFI_TIMING_MODE) &
-		ONFI_TIMING_MODE__VALUE))
-		return FAIL;
-
-	for (i = 5; i > 0; i--) {
-		if (ioread32(denali->flash_reg + ONFI_TIMING_MODE) &
-			(0x01 << i))
-			break;
-	}
-
-	nand_onfi_timing_set(denali, i);
-
-	/*
-	 * By now, all the ONFI devices we know support the page cache
-	 * rw feature. So here we enable the pipeline_rw_ahead feature
-	 */
-	/* iowrite32(1, denali->flash_reg + CACHE_WRITE_ENABLE); */
-	/* iowrite32(1, denali->flash_reg + CACHE_READ_ENABLE);  */
-
-	return PASS;
-}
-
-static void get_samsung_nand_para(struct denali_nand_info *denali,
-							uint8_t device_id)
-{
-	if (device_id == 0xd3) { /* Samsung K9WAG08U1A */
-		/* Set timing register values according to datasheet */
-		iowrite32(5, denali->flash_reg + ACC_CLKS);
-		iowrite32(20, denali->flash_reg + RE_2_WE);
-		iowrite32(12, denali->flash_reg + WE_2_RE);
-		iowrite32(14, denali->flash_reg + ADDR_2_DATA);
-		iowrite32(3, denali->flash_reg + RDWR_EN_LO_CNT);
-		iowrite32(2, denali->flash_reg + RDWR_EN_HI_CNT);
-		iowrite32(2, denali->flash_reg + CS_SETUP_CNT);
-	}
-}
-
-/*
  * Use the configuration feature register to determine the maximum number of
  * banks that the hardware supports.
  */
@@ -352,58 +201,6 @@ static void detect_max_banks(struct denali_nand_info *denali)
 		denali->max_banks <<= 1;
 }
 
-static uint16_t denali_nand_timing_set(struct denali_nand_info *denali)
-{
-	uint16_t status = PASS;
-	uint32_t id_bytes[8], addr;
-	uint8_t maf_id, device_id;
-	int i;
-
-	/*
-	 * Use read id method to get device ID and other params.
-	 * For some NAND chips, controller can't report the correct
-	 * device ID by reading from DEVICE_ID register
-	 */
-	addr = MODE_11 | BANK(denali->flash_bank);
-	index_addr(denali, addr | 0, 0x90);
-	index_addr(denali, addr | 1, 0);
-	for (i = 0; i < 8; i++)
-		index_addr_read_data(denali, addr | 2, &id_bytes[i]);
-	maf_id = id_bytes[0];
-	device_id = id_bytes[1];
-
-	if (ioread32(denali->flash_reg + ONFI_DEVICE_NO_OF_LUNS) &
-		ONFI_DEVICE_NO_OF_LUNS__ONFI_DEVICE) { /* ONFI 1.0 NAND */
-		if (FAIL == get_onfi_nand_para(denali))
-			return FAIL;
-	} else if (maf_id == 0xEC) { /* Samsung NAND */
-		get_samsung_nand_para(denali, device_id);
-	}
-
-	dev_info(denali->dev,
-			"Dump timing register values:\n"
-			"acc_clks: %d, re_2_we: %d, re_2_re: %d\n"
-			"we_2_re: %d, addr_2_data: %d, rdwr_en_lo_cnt: %d\n"
-			"rdwr_en_hi_cnt: %d, cs_setup_cnt: %d\n",
-			ioread32(denali->flash_reg + ACC_CLKS),
-			ioread32(denali->flash_reg + RE_2_WE),
-			ioread32(denali->flash_reg + RE_2_RE),
-			ioread32(denali->flash_reg + WE_2_RE),
-			ioread32(denali->flash_reg + ADDR_2_DATA),
-			ioread32(denali->flash_reg + RDWR_EN_LO_CNT),
-			ioread32(denali->flash_reg + RDWR_EN_HI_CNT),
-			ioread32(denali->flash_reg + CS_SETUP_CNT));
-
-	/*
-	 * If the user specified to override the default timings
-	 * with a specific ONFI mode, we apply those changes here.
-	 */
-	if (onfi_timing_mode != NAND_DEFAULT_TIMINGS)
-		nand_onfi_timing_set(denali, onfi_timing_mode);
-
-	return status;
-}
-
 static void denali_set_intr_modes(struct denali_nand_info *denali,
 					uint16_t INT_ENABLE)
 {
@@ -1209,7 +1006,122 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
 		break;
 	}
 }
-/* end NAND core entry points */
+
+#define DIV_ROUND_DOWN_ULL(ll, d) \
+	({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
+
+static int denali_setup_data_interface(struct mtd_info *mtd,
+				       const struct nand_data_interface *conf,
+				       bool check_only)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	const struct nand_sdr_timings *timings;
+	unsigned long t_clk;
+	int acc_clks, re_2_we, re_2_re, we_2_re, addr_2_data;
+	int rdwr_en_lo, rdwr_en_hi, rdwr_en_lo_hi, cs_setup;
+	int addr_2_data_mask;
+	uint32_t tmp;
+
+	timings = nand_get_sdr_timings(conf);
+	if (IS_ERR(timings))
+		return PTR_ERR(timings);
+
+	/* clk_x period in picoseconds */
+	t_clk = DIV_ROUND_DOWN_ULL(1000000000000ULL, denali->clk_x_rate);
+	if (!t_clk)
+		return -EINVAL;
+
+	if (check_only)
+		return 0;
+
+	/* tREA -> ACC_CLKS */
+	acc_clks = DIV_ROUND_UP(timings->tREA_max, t_clk);
+	acc_clks = min_t(int, acc_clks, ACC_CLKS__VALUE);
+
+	tmp = ioread32(denali->flash_reg + ACC_CLKS);
+	tmp &= ~ACC_CLKS__VALUE;
+	tmp |= acc_clks;
+	iowrite32(tmp, denali->flash_reg + ACC_CLKS);
+
+	/* tRWH -> RE_2_WE */
+	re_2_we = DIV_ROUND_UP(timings->tRHW_min, t_clk);
+	re_2_we = min_t(int, re_2_we, RE_2_WE__VALUE);
+
+	tmp = ioread32(denali->flash_reg + RE_2_WE);
+	tmp &= ~RE_2_WE__VALUE;
+	tmp |= re_2_we;
+	iowrite32(tmp, denali->flash_reg + RE_2_WE);
+
+	/* tRHZ -> RE_2_RE */
+	re_2_re = DIV_ROUND_UP(timings->tRHZ_max, t_clk);
+	re_2_re = min_t(int, re_2_re, RE_2_RE__VALUE);
+
+	tmp = ioread32(denali->flash_reg + RE_2_RE);
+	tmp &= ~RE_2_RE__VALUE;
+	tmp |= re_2_re;
+	iowrite32(tmp, denali->flash_reg + RE_2_RE);
+
+	/* tWHR -> WE_2_RE */
+	we_2_re = DIV_ROUND_UP(timings->tWHR_min, t_clk);
+	we_2_re = min_t(int, we_2_re, TWHR2_AND_WE_2_RE__WE_2_RE);
+
+	tmp = ioread32(denali->flash_reg + TWHR2_AND_WE_2_RE);
+	tmp &= ~TWHR2_AND_WE_2_RE__WE_2_RE;
+	tmp |= we_2_re;
+	iowrite32(tmp, denali->flash_reg + TWHR2_AND_WE_2_RE);
+
+	/* tADL -> ADDR_2_DATA */
+
+	/* for older versions, ADDR_2_DATA is only 6 bit wide */
+	addr_2_data_mask = TCWAW_AND_ADDR_2_DATA__ADDR_2_DATA;
+	if (denali->revision < 0x0501)
+		addr_2_data_mask >>= 1;
+
+	addr_2_data = DIV_ROUND_UP(timings->tADL_min, t_clk);
+	addr_2_data = min_t(int, addr_2_data, addr_2_data_mask);
+
+	tmp = ioread32(denali->flash_reg + TCWAW_AND_ADDR_2_DATA);
+	tmp &= ~addr_2_data_mask;
+	tmp |= addr_2_data;
+	iowrite32(tmp, denali->flash_reg + TCWAW_AND_ADDR_2_DATA);
+
+	/* tREH, tWH -> RDWR_EN_HI_CNT */
+	rdwr_en_hi = DIV_ROUND_UP(max(timings->tREH_min, timings->tWH_min),
+				  t_clk);
+	rdwr_en_hi = min_t(int, rdwr_en_hi, RDWR_EN_HI_CNT__VALUE);
+
+	tmp = ioread32(denali->flash_reg + RDWR_EN_HI_CNT);
+	tmp &= ~RDWR_EN_HI_CNT__VALUE;
+	tmp |= rdwr_en_hi;
+	iowrite32(tmp, denali->flash_reg + RDWR_EN_HI_CNT);
+
+	/* tRP, tWP -> RDWR_EN_LO_CNT */
+	rdwr_en_lo = DIV_ROUND_UP(max(timings->tRP_min, timings->tWP_min),
+				  t_clk);
+	rdwr_en_lo_hi = DIV_ROUND_UP(max(timings->tRC_min, timings->tWC_min),
+				     t_clk);
+	rdwr_en_lo_hi = max(rdwr_en_lo_hi, DENALI_CLK_X_MULT);
+	rdwr_en_lo = max(rdwr_en_lo, rdwr_en_lo_hi - rdwr_en_hi);
+	rdwr_en_lo = min_t(int, rdwr_en_lo, RDWR_EN_LO_CNT__VALUE);
+
+	tmp = ioread32(denali->flash_reg + RDWR_EN_LO_CNT);
+	tmp &= ~RDWR_EN_LO_CNT__VALUE;
+	tmp |= rdwr_en_lo;
+	iowrite32(tmp, denali->flash_reg + RDWR_EN_LO_CNT);
+
+	/* tCS, tCEA -> CS_SETUP_CNT */
+	cs_setup = max3((int)DIV_ROUND_UP(timings->tCS_min, t_clk) - rdwr_en_lo,
+			(int)DIV_ROUND_UP(timings->tCEA_max, t_clk) - acc_clks,
+			0);
+	cs_setup = min_t(int, cs_setup, CS_SETUP_CNT__VALUE);
+
+	tmp = ioread32(denali->flash_reg + CS_SETUP_CNT);
+	tmp &= ~CS_SETUP_CNT__VALUE;
+	tmp |= cs_setup;
+	iowrite32(tmp, denali->flash_reg + CS_SETUP_CNT);
+
+	return 0;
+}
 
 /* Initialization code to bring the device up to a known good state */
 static void denali_hw_init(struct denali_nand_info *denali)
@@ -1241,7 +1153,6 @@ static void denali_hw_init(struct denali_nand_info *denali)
 	/* Should set value for these registers when init */
 	iowrite32(0, denali->flash_reg + TWO_ROW_ADDR_CYCLES);
 	iowrite32(1, denali->flash_reg + ECC_ENABLE);
-	denali_nand_timing_set(denali);
 	denali_irq_init(denali);
 }
 
@@ -1416,17 +1327,6 @@ int denali_init(struct denali_nand_info *denali)
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	int ret;
 
-	if (denali->platform == INTEL_CE4100) {
-		/*
-		 * Due to a silicon limitation, we can only support
-		 * ONFI timing mode 1 and below.
-		 */
-		if (onfi_timing_mode < -1 || onfi_timing_mode > 1) {
-			pr_err("Intel CE4100 only supports ONFI timing mode 1 or below\n");
-			return -EINVAL;
-		}
-	}
-
 	/* allocate a temporary buffer for nand_scan_ident() */
 	denali->buf.buf = devm_kzalloc(denali->dev, PAGE_SIZE,
 					GFP_DMA | GFP_KERNEL);
@@ -1457,6 +1357,9 @@ int denali_init(struct denali_nand_info *denali)
 	chip->cmdfunc = denali_cmdfunc;
 	chip->read_byte = denali_read_byte;
 	chip->waitfunc = denali_waitfunc;
+	/* clk rate info is needed for setup_data_interface */
+	if (denali->clk_x_rate)
+		chip->setup_data_interface = denali_setup_data_interface;
 
 	/*
 	 * scan for NAND devices attached to the controller
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 0e4a8965f6f1..fb473895a79d 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -72,11 +72,14 @@
 #define GLOBAL_INT_ENABLE			0xf0
 #define     GLOBAL_INT_EN_FLAG				BIT(0)
 
-#define WE_2_RE					0x100
-#define     WE_2_RE__VALUE				GENMASK(5, 0)
+#define TWHR2_AND_WE_2_RE			0x100
+#define     TWHR2_AND_WE_2_RE__WE_2_RE			GENMASK(5, 0)
+#define     TWHR2_AND_WE_2_RE__TWHR2			GENMASK(13, 8)
 
-#define ADDR_2_DATA				0x110
-#define     ADDR_2_DATA__VALUE				GENMASK(5, 0)
+#define TCWAW_AND_ADDR_2_DATA			0x110
+/* The width of ADDR_2_DATA is 6 bit for old IP, 7 bit for new IP */
+#define     TCWAW_AND_ADDR_2_DATA__ADDR_2_DATA		GENMASK(6, 0)
+#define     TCWAW_AND_ADDR_2_DATA__TCWAW		GENMASK(13, 8)
 
 #define RE_2_WE					0x120
 #define     RE_2_WE__VALUE				GENMASK(5, 0)
@@ -128,6 +131,7 @@
 
 #define CS_SETUP_CNT				0x220
 #define     CS_SETUP_CNT__VALUE				GENMASK(4, 0)
+#define     CS_SETUP_CNT__TWB				GENMASK(17, 12)
 
 #define SPARE_AREA_SKIP_BYTES			0x230
 #define     SPARE_AREA_SKIP_BYTES__VALUE		GENMASK(5, 0)
@@ -294,16 +298,8 @@
 #define     CHNL_ACTIVE__CHANNEL2			BIT(2)
 #define     CHNL_ACTIVE__CHANNEL3			BIT(3)
 
-#define FAIL 1                  /*failed flag*/
 #define PASS 0                  /*success flag*/
 
-#define CLK_X  5
-#define CLK_MULTI 4
-
-#define ONFI_BLOOM_TIME         1
-#define MODE5_WORKAROUND        0
-
-
 #define MODE_00    0x00000000
 #define MODE_01    0x04000000
 #define MODE_10    0x08000000
@@ -316,14 +312,10 @@ struct nand_buf {
 	dma_addr_t dma_buf;
 };
 
-#define INTEL_CE4100	1
-#define INTEL_MRST	2
-#define DT		3
-
 struct denali_nand_info {
 	struct nand_chip nand;
+	unsigned long clk_x_rate;	/* bus interface clock rate */
 	int flash_bank; /* currently selected chip */
-	int platform;
 	struct nand_buf buf;
 	struct device *dev;
 	int page;
diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
index be598230c108..ebcce50f4005 100644
--- a/drivers/mtd/nand/denali_dt.c
+++ b/drivers/mtd/nand/denali_dt.c
@@ -96,7 +96,6 @@ static int denali_dt_probe(struct platform_device *pdev)
 		denali->ecc_caps = data->ecc_caps;
 	}
 
-	denali->platform = DT;
 	denali->dev = &pdev->dev;
 	denali->irq = platform_get_irq(pdev, 0);
 	if (denali->irq < 0) {
@@ -121,6 +120,8 @@ static int denali_dt_probe(struct platform_device *pdev)
 	}
 	clk_prepare_enable(dt->clk);
 
+	denali->clk_x_rate = clk_get_rate(dt->clk);
+
 	ret = denali_init(denali);
 	if (ret)
 		goto out_disable_clk;
diff --git a/drivers/mtd/nand/denali_pci.c b/drivers/mtd/nand/denali_pci.c
index 37dc0934c24c..6217525c1000 100644
--- a/drivers/mtd/nand/denali_pci.c
+++ b/drivers/mtd/nand/denali_pci.c
@@ -19,6 +19,9 @@
 
 #define DENALI_NAND_NAME    "denali-nand-pci"
 
+#define INTEL_CE4100	1
+#define INTEL_MRST	2
+
 /* List of platforms this NAND controller has be integrated into */
 static const struct pci_device_id denali_pci_ids[] = {
 	{ PCI_VDEVICE(INTEL, 0x0701), INTEL_CE4100 },
@@ -47,13 +50,11 @@ static int denali_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	}
 
 	if (id->driver_data == INTEL_CE4100) {
-		denali->platform = INTEL_CE4100;
 		mem_base = pci_resource_start(dev, 0);
 		mem_len = pci_resource_len(dev, 1);
 		csr_base = pci_resource_start(dev, 1);
 		csr_len = pci_resource_len(dev, 1);
 	} else {
-		denali->platform = INTEL_MRST;
 		csr_base = pci_resource_start(dev, 0);
 		csr_len = pci_resource_len(dev, 0);
 		mem_base = pci_resource_start(dev, 1);
@@ -69,6 +70,7 @@ static int denali_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	denali->irq = dev->irq;
 	denali->ecc_caps = &denali_pci_ecc_caps;
 	denali->nand.ecc.options |= NAND_ECC_MAXIMIZE;
+	denali->clk_x_rate = 200000000;		/* 200 MHz */
 
 	ret = pci_request_regions(dev, DENALI_NAND_NAME);
 	if (ret) {
-- 
2.7.4

[PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Masahiro Yamada]

Simplify the interrupt handling and fix issues:

- The register field view of INTR_EN / INTR_STATUS is different
  among IP versions.  The global macro DENALI_IRQ_ALL is hard-coded
  for Intel platforms.  The interrupt mask should be determined at
  run-time depending on the running platform.

- wait_for_irq() loops do {} while() until interested flags are
  asserted.  The logic can be simplified.

- The spin_lock() guard seems too complex (and suspicious in a race
  condition if wait_for_completion_timeout() bails out by timeout).

- denali->complete is reused again and again, but reinit_completion()
  is missing.  Add it.

Re-work the code to make it more robust and easier to handle.

While we are here, also rename the jump label "failed_req_irq" to
more appropriate "disable_irq".

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 316 +++++++++++++++++-----------------------------
 drivers/mtd/nand/denali.h |   1 +
 2 files changed, 116 insertions(+), 201 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 8ad1e96f6d03..62798e6d7009 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -31,21 +31,6 @@ MODULE_LICENSE("GPL");
 #define DENALI_NAND_NAME    "denali-nand"
 
 /*
- * We define a macro here that combines all interrupts this driver uses into
- * a single constant value, for convenience.
- */
-#define DENALI_IRQ_ALL	(INTR__DMA_CMD_COMP | \
-			INTR__ECC_TRANSACTION_DONE | \
-			INTR__ECC_ERR | \
-			INTR__PROGRAM_FAIL | \
-			INTR__LOAD_COMP | \
-			INTR__PROGRAM_COMP | \
-			INTR__TIME_OUT | \
-			INTR__ERASE_FAIL | \
-			INTR__RST_COMP | \
-			INTR__ERASE_COMP)
-
-/*
  * indicates whether or not the internal value for the flash bank is
  * valid or not
  */
@@ -71,20 +56,14 @@ static inline struct denali_nand_info *mtd_to_denali(struct mtd_info *mtd)
 #define DENALI_READ	0
 #define DENALI_WRITE	0x100
 
+#define DENALI_NR_BANKS		4
+
 /*
  * this is a helper macro that allows us to
  * format the bank into the proper bits for the controller
  */
 #define BANK(x) ((x) << 24)
 
-/* forward declarations */
-static void clear_interrupts(struct denali_nand_info *denali);
-static uint32_t wait_for_irq(struct denali_nand_info *denali,
-							uint32_t irq_mask);
-static void denali_irq_enable(struct denali_nand_info *denali,
-							uint32_t int_mask);
-static uint32_t read_interrupt_status(struct denali_nand_info *denali);
-
 /*
  * The bus interface clock, clk_x, is phase aligned with the core clock.  The
  * clk_x is an integral multiple N of the core clk.  The value N is configured
@@ -143,22 +122,6 @@ static void read_status(struct denali_nand_info *denali)
 		write_byte_to_buf(denali, 0);
 }
 
-/* resets a specific device connected to the core */
-static void reset_bank(struct denali_nand_info *denali)
-{
-	uint32_t irq_status;
-	uint32_t irq_mask = INTR__RST_COMP | INTR__TIME_OUT;
-
-	clear_interrupts(denali);
-
-	iowrite32(1 << denali->flash_bank, denali->flash_reg + DEVICE_RESET);
-
-	irq_status = wait_for_irq(denali, irq_mask);
-
-	if (irq_status & INTR__TIME_OUT)
-		dev_err(denali->dev, "reset bank failed.\n");
-}
-
 /* Reset the flash controller */
 static uint16_t denali_nand_reset(struct denali_nand_info *denali)
 {
@@ -201,169 +164,123 @@ static void detect_max_banks(struct denali_nand_info *denali)
 		denali->max_banks <<= 1;
 }
 
-static void denali_set_intr_modes(struct denali_nand_info *denali,
-					uint16_t INT_ENABLE)
+static void denali_enable_irq(struct denali_nand_info *denali)
 {
-	if (INT_ENABLE)
-		iowrite32(1, denali->flash_reg + GLOBAL_INT_ENABLE);
-	else
-		iowrite32(0, denali->flash_reg + GLOBAL_INT_ENABLE);
-}
+	int i;
 
-/*
- * validation function to verify that the controlling software is making
- * a valid request
- */
-static inline bool is_flash_bank_valid(int flash_bank)
-{
-	return flash_bank >= 0 && flash_bank < 4;
+	for (i = 0; i < DENALI_NR_BANKS; i++)
+		iowrite32(U32_MAX, denali->flash_reg + INTR_EN(i));
+	iowrite32(GLOBAL_INT_EN_FLAG, denali->flash_reg + GLOBAL_INT_ENABLE);
 }
 
-static void denali_irq_init(struct denali_nand_info *denali)
+static void denali_disable_irq(struct denali_nand_info *denali)
 {
-	uint32_t int_mask;
 	int i;
 
-	/* Disable global interrupts */
-	denali_set_intr_modes(denali, false);
-
-	int_mask = DENALI_IRQ_ALL;
-
-	/* Clear all status bits */
-	for (i = 0; i < denali->max_banks; ++i)
-		iowrite32(0xFFFF, denali->flash_reg + INTR_STATUS(i));
-
-	denali_irq_enable(denali, int_mask);
+	for (i = 0; i < DENALI_NR_BANKS; i++)
+		iowrite32(0, denali->flash_reg + INTR_EN(i));
+	iowrite32(0, denali->flash_reg + GLOBAL_INT_ENABLE);
 }
 
-static void denali_irq_cleanup(int irqnum, struct denali_nand_info *denali)
+static void denali_clear_irq(struct denali_nand_info *denali,
+			     int bank, uint32_t irq_status)
 {
-	denali_set_intr_modes(denali, false);
+	/* write one to clear bits */
+	iowrite32(irq_status, denali->flash_reg + INTR_STATUS(bank));
 }
 
-static void denali_irq_enable(struct denali_nand_info *denali,
-							uint32_t int_mask)
+static void denali_clear_irq_all(struct denali_nand_info *denali)
 {
 	int i;
 
-	for (i = 0; i < denali->max_banks; ++i)
-		iowrite32(int_mask, denali->flash_reg + INTR_EN(i));
+	for (i = 0; i < DENALI_NR_BANKS; i++)
+		denali_clear_irq(denali, i, U32_MAX);
 }
 
-/*
- * This function only returns when an interrupt that this driver cares about
- * occurs. This is to reduce the overhead of servicing interrupts
- */
-static inline uint32_t denali_irq_detected(struct denali_nand_info *denali)
+static irqreturn_t denali_isr(int irq, void *dev_id)
 {
-	return read_interrupt_status(denali) & DENALI_IRQ_ALL;
-}
+	struct denali_nand_info *denali = dev_id;
+	irqreturn_t ret = IRQ_NONE;
+	uint32_t irq_status;
+	int i;
 
-/* Interrupts are cleared by writing a 1 to the appropriate status bit */
-static inline void clear_interrupt(struct denali_nand_info *denali,
-							uint32_t irq_mask)
-{
-	uint32_t intr_status_reg;
+	spin_lock(&denali->irq_lock);
 
-	intr_status_reg = INTR_STATUS(denali->flash_bank);
+	for (i = 0; i < DENALI_NR_BANKS; i++) {
+		irq_status = ioread32(denali->flash_reg + INTR_STATUS(i));
+		if (irq_status)
+			ret = IRQ_HANDLED;
 
-	iowrite32(irq_mask, denali->flash_reg + intr_status_reg);
-}
+		denali_clear_irq(denali, i, irq_status);
 
-static void clear_interrupts(struct denali_nand_info *denali)
-{
-	uint32_t status;
+		if (i != denali->flash_bank)
+			continue;
+
+		denali->irq_status |= irq_status;
 
-	spin_lock_irq(&denali->irq_lock);
+		if (denali->irq_status & denali->irq_mask)
+			complete(&denali->complete);
+	}
 
-	status = read_interrupt_status(denali);
-	clear_interrupt(denali, status);
+	spin_unlock(&denali->irq_lock);
 
-	denali->irq_status = 0x0;
-	spin_unlock_irq(&denali->irq_lock);
+	return ret;
 }
 
-static uint32_t read_interrupt_status(struct denali_nand_info *denali)
+static void denali_reset_irq(struct denali_nand_info *denali)
 {
-	uint32_t intr_status_reg;
-
-	intr_status_reg = INTR_STATUS(denali->flash_bank);
+	unsigned long flags;
 
-	return ioread32(denali->flash_reg + intr_status_reg);
+	spin_lock_irqsave(&denali->irq_lock, flags);
+	denali->irq_status = 0;
+	denali->irq_mask = 0;
+	spin_unlock_irqrestore(&denali->irq_lock, flags);
 }
 
-/*
- * This is the interrupt service routine. It handles all interrupts
- * sent to this device. Note that on CE4100, this is a shared interrupt.
- */
-static irqreturn_t denali_isr(int irq, void *dev_id)
+static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
+				    uint32_t irq_mask)
 {
-	struct denali_nand_info *denali = dev_id;
+	unsigned long time_left, flags;
 	uint32_t irq_status;
-	irqreturn_t result = IRQ_NONE;
 
-	spin_lock(&denali->irq_lock);
+	spin_lock_irqsave(&denali->irq_lock, flags);
 
-	/* check to see if a valid NAND chip has been selected. */
-	if (is_flash_bank_valid(denali->flash_bank)) {
-		/*
-		 * check to see if controller generated the interrupt,
-		 * since this is a shared interrupt
-		 */
-		irq_status = denali_irq_detected(denali);
-		if (irq_status != 0) {
-			/* handle interrupt */
-			/* first acknowledge it */
-			clear_interrupt(denali, irq_status);
-			/*
-			 * store the status in the device context for someone
-			 * to read
-			 */
-			denali->irq_status |= irq_status;
-			/* notify anyone who cares that it happened */
-			complete(&denali->complete);
-			/* tell the OS that we've handled this */
-			result = IRQ_HANDLED;
-		}
+	irq_status = denali->irq_status;
+
+	if (irq_mask & irq_status) {
+		spin_unlock_irqrestore(&denali->irq_lock, flags);
+		return irq_status;
 	}
-	spin_unlock(&denali->irq_lock);
-	return result;
+
+	denali->irq_mask = irq_mask;
+	reinit_completion(&denali->complete);
+	spin_unlock_irqrestore(&denali->irq_lock, flags);
+
+	time_left = wait_for_completion_timeout(&denali->complete,
+						msecs_to_jiffies(1000));
+	if (!time_left) {
+		dev_err(denali->dev, "timeout while waiting for irq 0x%x\n",
+			denali->irq_mask);
+		return 0;
+	}
+
+	return denali->irq_status;
 }
 
-static uint32_t wait_for_irq(struct denali_nand_info *denali, uint32_t irq_mask)
+/* resets a specific device connected to the core */
+static void reset_bank(struct denali_nand_info *denali)
 {
-	unsigned long comp_res;
-	uint32_t intr_status;
-	unsigned long timeout = msecs_to_jiffies(1000);
+	uint32_t irq_status;
 
-	do {
-		comp_res =
-			wait_for_completion_timeout(&denali->complete, timeout);
-		spin_lock_irq(&denali->irq_lock);
-		intr_status = denali->irq_status;
-
-		if (intr_status & irq_mask) {
-			denali->irq_status &= ~irq_mask;
-			spin_unlock_irq(&denali->irq_lock);
-			/* our interrupt was detected */
-			break;
-		}
+	denali_reset_irq(denali);
 
-		/*
-		 * these are not the interrupts you are looking for -
-		 * need to wait again
-		 */
-		spin_unlock_irq(&denali->irq_lock);
-	} while (comp_res != 0);
+	iowrite32(1 << denali->flash_bank, denali->flash_reg + DEVICE_RESET);
 
-	if (comp_res == 0) {
-		/* timeout */
-		pr_err("timeout occurred, status = 0x%x, mask = 0x%x\n",
-				intr_status, irq_mask);
+	irq_status = denali_wait_for_irq(denali,
+					 INTR__RST_COMP | INTR__TIME_OUT);
 
-		intr_status = 0;
-	}
-	return intr_status;
+	if (!(irq_status & INTR__RST_COMP))
+		dev_err(denali->dev, "reset bank failed.\n");
 }
 
 /*
@@ -397,7 +314,7 @@ static int denali_send_pipeline_cmd(struct denali_nand_info *denali,
 
 	setup_ecc_for_xfer(denali, ecc_en, transfer_spare);
 
-	clear_interrupts(denali);
+	denali_reset_irq(denali);
 
 	addr = BANK(denali->flash_bank) | denali->page;
 
@@ -479,9 +396,9 @@ static int write_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 		write_data_to_flash_mem(denali, buf, mtd->oobsize);
 
 		/* wait for operation to complete */
-		irq_status = wait_for_irq(denali, irq_mask);
+		irq_status = denali_wait_for_irq(denali, irq_mask);
 
-		if (irq_status == 0) {
+		if (!(irq_status & INTR__PROGRAM_COMP)) {
 			dev_err(denali->dev, "OOB write failed\n");
 			status = -EIO;
 		}
@@ -510,9 +427,9 @@ static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 		 * can always use status0 bit as the
 		 * mask is identical for each bank.
 		 */
-		irq_status = wait_for_irq(denali, irq_mask);
+		irq_status = denali_wait_for_irq(denali, irq_mask);
 
-		if (irq_status == 0)
+		if (!(irq_status & INTR__LOAD_COMP))
 			dev_err(denali->dev, "page on OOB timeout %d\n",
 					denali->page);
 
@@ -620,9 +537,9 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd,
 	unsigned int err_byte, err_sector, err_device;
 	uint8_t err_cor_value;
 	unsigned int prev_sector = 0;
+	uint32_t irq_status;
 
-	/* read the ECC errors. we'll ignore them for now */
-	denali_set_intr_modes(denali, false);
+	denali_reset_irq(denali);
 
 	do {
 		err_addr = ioread32(denali->flash_reg + ECC_ERROR_ADDRESS);
@@ -674,10 +591,9 @@ static int denali_sw_ecc_fixup(struct mtd_info *mtd,
 	 * ECC_TRANSACTION_DONE interrupt, so here just wait for
 	 * a while for this interrupt
 	 */
-	while (!(read_interrupt_status(denali) & INTR__ECC_TRANSACTION_DONE))
-		cpu_relax();
-	clear_interrupts(denali);
-	denali_set_intr_modes(denali, true);
+	irq_status = denali_wait_for_irq(denali, INTR__ECC_TRANSACTION_DONE);
+	if (!(irq_status & INTR__ECC_TRANSACTION_DONE))
+		return -EIO;
 
 	return max_bitflips;
 }
@@ -778,15 +694,14 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 
 	dma_sync_single_for_device(denali->dev, addr, size, DMA_TO_DEVICE);
 
-	clear_interrupts(denali);
+	denali_reset_irq(denali);
 	denali_enable_dma(denali, true);
 
 	denali_setup_dma(denali, DENALI_WRITE);
 
 	/* wait for operation to complete */
-	irq_status = wait_for_irq(denali, irq_mask);
-
-	if (irq_status == 0) {
+	irq_status = denali_wait_for_irq(denali, irq_mask);
+	if (!(irq_status & INTR__DMA_CMD_COMP)) {
 		dev_err(denali->dev, "timeout on write_page (type = %d)\n",
 			raw_xfer);
 		ret = -EIO;
@@ -865,11 +780,11 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 	denali_enable_dma(denali, true);
 	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
 
-	clear_interrupts(denali);
+	denali_reset_irq(denali);
 	denali_setup_dma(denali, DENALI_READ);
 
 	/* wait for operation to complete */
-	irq_status = wait_for_irq(denali, irq_mask);
+	irq_status = denali_wait_for_irq(denali, irq_mask);
 
 	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_FROM_DEVICE);
 
@@ -901,6 +816,7 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	dma_addr_t addr = denali->buf.dma_buf;
 	size_t size = mtd->writesize + mtd->oobsize;
 	uint32_t irq_mask = INTR__DMA_CMD_COMP;
+	uint32_t irq_status;
 
 	denali->page = page;
 
@@ -909,11 +825,13 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 
 	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
 
-	clear_interrupts(denali);
+	denali_reset_irq(denali);
 	denali_setup_dma(denali, DENALI_READ);
 
 	/* wait for operation to complete */
-	wait_for_irq(denali, irq_mask);
+	irq_status = denali_wait_for_irq(denali, irq_mask);
+	if (irq_status & INTR__DMA_CMD_COMP)
+		return -ETIMEDOUT;
 
 	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_FROM_DEVICE);
 
@@ -940,9 +858,7 @@ static void denali_select_chip(struct mtd_info *mtd, int chip)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
 
-	spin_lock_irq(&denali->irq_lock);
 	denali->flash_bank = chip;
-	spin_unlock_irq(&denali->irq_lock);
 }
 
 static int denali_waitfunc(struct mtd_info *mtd, struct nand_chip *chip)
@@ -953,19 +869,19 @@ static int denali_waitfunc(struct mtd_info *mtd, struct nand_chip *chip)
 static int denali_erase(struct mtd_info *mtd, int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
-
 	uint32_t cmd, irq_status;
 
-	clear_interrupts(denali);
+	denali_reset_irq(denali);
 
 	/* setup page read request for access type */
 	cmd = MODE_10 | BANK(denali->flash_bank) | page;
 	index_addr(denali, cmd, 0x1);
 
 	/* wait for erase to complete or failure to occur */
-	irq_status = wait_for_irq(denali, INTR__ERASE_COMP | INTR__ERASE_FAIL);
+	irq_status = denali_wait_for_irq(denali,
+					 INTR__ERASE_COMP | INTR__ERASE_FAIL);
 
-	return irq_status & INTR__ERASE_FAIL ? NAND_STATUS_FAIL : PASS;
+	return irq_status & INTR__ERASE_COMP ? 0 : NAND_STATUS_FAIL;
 }
 
 static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
@@ -1153,7 +1069,6 @@ static void denali_hw_init(struct denali_nand_info *denali)
 	/* Should set value for these registers when init */
 	iowrite32(0, denali->flash_reg + TWO_ROW_ADDR_CYCLES);
 	iowrite32(1, denali->flash_reg + ECC_ENABLE);
-	denali_irq_init(denali);
 }
 
 int denali_calc_ecc_bytes(int step_size, int strength)
@@ -1265,9 +1180,6 @@ static void denali_drv_init(struct denali_nand_info *denali)
 
 	/* indicate that MTD has not selected a valid bank yet */
 	denali->flash_bank = CHIP_SELECT_INVALID;
-
-	/* initialize our irq_status variable to indicate no interrupts */
-	denali->irq_status = 0;
 }
 
 static int denali_multidev_fixup(struct denali_nand_info *denali)
@@ -1337,6 +1249,8 @@ int denali_init(struct denali_nand_info *denali)
 	denali_hw_init(denali);
 	denali_drv_init(denali);
 
+	denali_clear_irq_all(denali);
+
 	/* Request IRQ after all the hardware initialization is finished */
 	ret = devm_request_irq(denali->dev, denali->irq, denali_isr,
 			       IRQF_SHARED, DENALI_NAND_NAME, denali);
@@ -1345,8 +1259,8 @@ int denali_init(struct denali_nand_info *denali)
 		return ret;
 	}
 
-	/* now that our ISR is registered, we can enable interrupts */
-	denali_set_intr_modes(denali, true);
+	denali_enable_irq(denali);
+
 	nand_set_flash_node(chip, denali->dev->of_node);
 	/* Fallback to the default name if DT did not give "label" property */
 	if (!mtd->name)
@@ -1368,7 +1282,7 @@ int denali_init(struct denali_nand_info *denali)
 	 */
 	ret = nand_scan_ident(mtd, denali->max_banks, NULL);
 	if (ret)
-		goto failed_req_irq;
+		goto disable_irq;
 
 	/* allocate the right size buffer now */
 	devm_kfree(denali->dev, denali->buf.buf);
@@ -1377,7 +1291,7 @@ int denali_init(struct denali_nand_info *denali)
 			     GFP_KERNEL);
 	if (!denali->buf.buf) {
 		ret = -ENOMEM;
-		goto failed_req_irq;
+		goto disable_irq;
 	}
 
 	ret = dma_set_mask(denali->dev,
@@ -1385,7 +1299,7 @@ int denali_init(struct denali_nand_info *denali)
 					64 : 32));
 	if (ret) {
 		dev_err(denali->dev, "No usable DMA configuration\n");
-		goto failed_req_irq;
+		goto disable_irq;
 	}
 
 	denali->buf.dma_buf = dma_map_single(denali->dev, denali->buf.buf,
@@ -1394,7 +1308,7 @@ int denali_init(struct denali_nand_info *denali)
 	if (dma_mapping_error(denali->dev, denali->buf.dma_buf)) {
 		dev_err(denali->dev, "Failed to map DMA buffer\n");
 		ret = -EIO;
-		goto failed_req_irq;
+		goto disable_irq;
 	}
 
 	/*
@@ -1418,7 +1332,7 @@ int denali_init(struct denali_nand_info *denali)
 	ret = denali_ecc_setup(mtd, chip, denali);
 	if (ret) {
 		dev_err(denali->dev, "Failed to setup ECC settings.\n");
-		goto failed_req_irq;
+		goto disable_irq;
 	}
 
 	dev_dbg(denali->dev,
@@ -1452,21 +1366,21 @@ int denali_init(struct denali_nand_info *denali)
 
 	ret = denali_multidev_fixup(denali);
 	if (ret)
-		goto failed_req_irq;
+		goto disable_irq;
 
 	ret = nand_scan_tail(mtd);
 	if (ret)
-		goto failed_req_irq;
+		goto disable_irq;
 
 	ret = mtd_device_register(mtd, NULL, 0);
 	if (ret) {
 		dev_err(denali->dev, "Failed to register MTD: %d\n", ret);
-		goto failed_req_irq;
+		goto disable_irq;
 	}
 	return 0;
 
-failed_req_irq:
-	denali_irq_cleanup(denali->irq, denali);
+disable_irq:
+	denali_disable_irq(denali);
 
 	return ret;
 }
@@ -1484,7 +1398,7 @@ void denali_remove(struct denali_nand_info *denali)
 	int bufsize = mtd->writesize + mtd->oobsize;
 
 	nand_release(mtd);
-	denali_irq_cleanup(denali->irq, denali);
+	denali_disable_irq(denali);
 	dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize,
 			 DMA_BIDIRECTIONAL);
 }
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index fb473895a79d..a0ac0f84f8b5 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -325,6 +325,7 @@ struct denali_nand_info {
 	/* elements used by ISR */
 	struct completion complete;
 	spinlock_t irq_lock;
+	uint32_t irq_mask;
 	uint32_t irq_status;
 	int irq;
 
-- 
2.7.4

[PATCH v5 11/23] mtd: nand: denali: fix NAND_CMD_STATUS handling

[Masahiro Yamada]

The current NAND_CMD_STATUS handling is weird; it just reads the
WRITE_PROTECT register, and returns NAND_STATUS_WP if it is set.

It does not send Read Status (0x70) command, so it is not helpful
for checking the current device status.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 62798e6d7009..94beab57c145 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -107,21 +107,6 @@ static void write_byte_to_buf(struct denali_nand_info *denali, uint8_t byte)
 	denali->buf.buf[denali->buf.tail++] = byte;
 }
 
-/* reads the status of the device */
-static void read_status(struct denali_nand_info *denali)
-{
-	uint32_t cmd;
-
-	/* initialize the data buffer to store status */
-	reset_buf(denali);
-
-	cmd = ioread32(denali->flash_reg + WRITE_PROTECT);
-	if (cmd)
-		write_byte_to_buf(denali, NAND_STATUS_WP);
-	else
-		write_byte_to_buf(denali, 0);
-}
-
 /* Reset the flash controller */
 static uint16_t denali_nand_reset(struct denali_nand_info *denali)
 {
@@ -893,7 +878,11 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
 
 	switch (cmd) {
 	case NAND_CMD_STATUS:
-		read_status(denali);
+		reset_buf(denali);
+		addr = MODE_11 | BANK(denali->flash_bank);
+		index_addr(denali, addr | 0, cmd);
+		index_addr_read_data(denali, addr | 2, &id);
+		write_byte_to_buf(denali, id);
 		break;
 	case NAND_CMD_READID:
 	case NAND_CMD_PARAM:
-- 
2.7.4

[PATCH v5 12/23] mtd: nand: denali: fix NAND_CMD_PARAM handling

[Masahiro Yamada]

NAND_CMD_PARAM is not working at all due to multiple bugs.

[1] The command 0x90 issued instead of 0xec

The command code 0x90 is hard-code as
   index_addr(denali, addr | 0, 0x90)
So, Read ID (0x90) command is sent to the device instead of Read
Parameter Page (0xec).

[2] only first 8 bytes are read

Even if [1] is fixed, the current implementation is problematic.
The only first 8 bytes are read by MAP11 command, and put into the
temporal buffer:

    for (i = 0; i < 8; i++) {
            index_addr_read_data(denali, addr | 2, &id);
            write_byte_to_buf(denali, id);
    }

Obviously, this is not sufficient for NAND_CMD_PARAM; the ONFi
parameters are 256-byte long.  This is still insufficient.
As you see in nand_flash_detect_onfi() reads out (256 * 3) bytes
at maximum (Redundant Parameter Pages).  However, changing the loop
to for (i = 0; i < 768; i++) is a crazy idea.  At the point of the
chip->cmdfunc() call, we cannot know how many times chip->read_byte()
will be called.  So, pre-reading enough number of bytes in the
chip->cmdfunc() is a design mistake.

[3] no wait for R/B#

The current code handles NAND_CMD_READID and NAND_CMD_PARAM in the
same way, but this is also wrong.  The difference between them is
that Read ID command does not toggle R/B# whereas the Read Parameter
Page command requires R/B#.  Without the wait for R/B# interrupt,
wrong data are retrieved.

In order to fix those problems, data read cycle of the MAP11 command
has been moved to chip->read_byte().  Data are read out as needed.
Another good thing is early temporal buffer is not needed any more.
The ugly devm_kzalloc()/devm_kfree() dance has been killed.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 95 +++++++++++++++--------------------------------
 drivers/mtd/nand/denali.h |  2 -
 2 files changed, 30 insertions(+), 67 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 94beab57c145..c3382954cf27 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -85,28 +85,6 @@ static void index_addr(struct denali_nand_info *denali,
 	iowrite32(data, denali->flash_mem + 0x10);
 }
 
-/* Perform an indexed read of the device */
-static void index_addr_read_data(struct denali_nand_info *denali,
-				 uint32_t address, uint32_t *pdata)
-{
-	iowrite32(address, denali->flash_mem);
-	*pdata = ioread32(denali->flash_mem + 0x10);
-}
-
-/*
- * We need to buffer some data for some of the NAND core routines.
- * The operations manage buffering that data.
- */
-static void reset_buf(struct denali_nand_info *denali)
-{
-	denali->buf.head = denali->buf.tail = 0;
-}
-
-static void write_byte_to_buf(struct denali_nand_info *denali, uint8_t byte)
-{
-	denali->buf.buf[denali->buf.tail++] = byte;
-}
-
 /* Reset the flash controller */
 static uint16_t denali_nand_reset(struct denali_nand_info *denali)
 {
@@ -286,6 +264,15 @@ static void setup_ecc_for_xfer(struct denali_nand_info *denali, bool ecc_en,
 	iowrite32(transfer_spare_flag, denali->flash_reg + TRANSFER_SPARE_REG);
 }
 
+static uint8_t denali_read_byte(struct mtd_info *mtd)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+
+	iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);
+
+	return ioread32(denali->flash_mem + 0x10);
+}
+
 /*
  * sends a pipeline command operation to the controller. See the Denali NAND
  * controller's user guide for more information (section 4.2.3.6).
@@ -828,17 +815,6 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	return 0;
 }
 
-static uint8_t denali_read_byte(struct mtd_info *mtd)
-{
-	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	uint8_t result = 0xff;
-
-	if (denali->buf.head < denali->buf.tail)
-		result = denali->buf.buf[denali->buf.head++];
-
-	return result;
-}
-
 static void denali_select_chip(struct mtd_info *mtd, int chip)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
@@ -873,43 +849,40 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
 			   int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	uint32_t addr, id;
-	int i;
+	uint32_t addr, irq_status;
+	int wait_ready = 0;
 
 	switch (cmd) {
-	case NAND_CMD_STATUS:
-		reset_buf(denali);
-		addr = MODE_11 | BANK(denali->flash_bank);
-		index_addr(denali, addr | 0, cmd);
-		index_addr_read_data(denali, addr | 2, &id);
-		write_byte_to_buf(denali, id);
+	case NAND_CMD_PARAM:
+		wait_ready = 1;
 		break;
+	case NAND_CMD_STATUS:
 	case NAND_CMD_READID:
-	case NAND_CMD_PARAM:
-		reset_buf(denali);
-		/*
-		 * sometimes ManufactureId read from register is not right
-		 * e.g. some of Micron MT29F32G08QAA MLC NAND chips
-		 * So here we send READID cmd to NAND insteand
-		 */
-		addr = MODE_11 | BANK(denali->flash_bank);
-		index_addr(denali, addr | 0, 0x90);
-		index_addr(denali, addr | 1, col);
-		for (i = 0; i < 8; i++) {
-			index_addr_read_data(denali, addr | 2, &id);
-			write_byte_to_buf(denali, id);
-		}
 		break;
 	case NAND_CMD_RESET:
 		reset_bank(denali);
 		break;
 	case NAND_CMD_READOOB:
 		/* TODO: Read OOB data */
-		break;
+		return;
 	default:
 		pr_err(": unsupported command received 0x%x\n", cmd);
-		break;
+		return;
 	}
+
+	denali_reset_irq(denali);
+
+	addr = MODE_11 | BANK(denali->flash_bank);
+	index_addr(denali, addr | 0, cmd);
+	if (col != -1)
+		index_addr(denali, addr | 1, col);
+
+	if (!wait_ready)
+		return;
+
+	irq_status = denali_wait_for_irq(denali, INTR__INT_ACT);
+	if (!(irq_status & INTR__INT_ACT))
+		dev_err(denali->dev, "failed to issue command 0x%x\n", cmd);
 }
 
 #define DIV_ROUND_DOWN_ULL(ll, d) \
@@ -1228,12 +1201,6 @@ int denali_init(struct denali_nand_info *denali)
 	struct mtd_info *mtd = nand_to_mtd(chip);
 	int ret;
 
-	/* allocate a temporary buffer for nand_scan_ident() */
-	denali->buf.buf = devm_kzalloc(denali->dev, PAGE_SIZE,
-					GFP_DMA | GFP_KERNEL);
-	if (!denali->buf.buf)
-		return -ENOMEM;
-
 	mtd->dev.parent = denali->dev;
 	denali_hw_init(denali);
 	denali_drv_init(denali);
@@ -1273,8 +1240,6 @@ int denali_init(struct denali_nand_info *denali)
 	if (ret)
 		goto disable_irq;
 
-	/* allocate the right size buffer now */
-	devm_kfree(denali->dev, denali->buf.buf);
 	denali->buf.buf = devm_kzalloc(denali->dev,
 			     mtd->writesize + mtd->oobsize,
 			     GFP_KERNEL);
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index a0ac0f84f8b5..a84d8784ee98 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -306,8 +306,6 @@
 #define MODE_11    0x0C000000
 
 struct nand_buf {
-	int head;
-	int tail;
 	uint8_t *buf;
 	dma_addr_t dma_buf;
 };
-- 
2.7.4

[PATCH v5 13/23] mtd: nand: denali: switch over to cmd_ctrl instead of cmdfunc

[Masahiro Yamada]

The NAND_CMD_SET_FEATURES support is missing from denali_cmdfunc().
This is needed for nand_onfi_set_features().

Besides, we see /* TODO: Read OOB data */ comment line.

It would be possible to add more commands along with the current
implementation, but having ->cmd_ctrl() seems a better approach from
the discussion with Boris [1].

Rely on the default ->cmdfunc() from the framework and implement the
driver's own ->cmd_ctrl().

Also add ->write_byte(), which is needed for write direction commands.

[1] https://lkml.org/lkml/2017/3/15/97

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 104 +++++++++++++++++++++++-----------------------
 1 file changed, 52 insertions(+), 52 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index c3382954cf27..95bce6b341d7 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -230,20 +230,16 @@ static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
 	return denali->irq_status;
 }
 
-/* resets a specific device connected to the core */
-static void reset_bank(struct denali_nand_info *denali)
+static uint32_t denali_check_irq(struct denali_nand_info *denali)
 {
+	unsigned long flags;
 	uint32_t irq_status;
 
-	denali_reset_irq(denali);
-
-	iowrite32(1 << denali->flash_bank, denali->flash_reg + DEVICE_RESET);
-
-	irq_status = denali_wait_for_irq(denali,
-					 INTR__RST_COMP | INTR__TIME_OUT);
+	spin_lock_irqsave(&denali->irq_lock, flags);
+	irq_status = denali->irq_status;
+	spin_unlock_irqrestore(&denali->irq_lock, flags);
 
-	if (!(irq_status & INTR__RST_COMP))
-		dev_err(denali->dev, "reset bank failed.\n");
+	return irq_status;
 }
 
 /*
@@ -273,6 +269,42 @@ static uint8_t denali_read_byte(struct mtd_info *mtd)
 	return ioread32(denali->flash_mem + 0x10);
 }
 
+static void denali_write_byte(struct mtd_info *mtd, uint8_t byte)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+
+	index_addr(denali, MODE_11 | BANK(denali->flash_bank) | 2, byte);
+}
+
+static void denali_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	uint32_t type;
+
+	if (ctrl & NAND_CLE)
+		type = 0;
+	else if (ctrl & NAND_ALE)
+		type = 1;
+	else
+		return;
+
+	/*
+	 * Some commands are followed by chip->dev_ready or chip->waitfunc.
+	 * irq_status must be cleared here to catch the R/B# interrupt later.
+	 */
+	if (ctrl & NAND_CTRL_CHANGE)
+		denali_reset_irq(denali);
+
+	index_addr(denali, MODE_11 | BANK(denali->flash_bank) | type, dat);
+}
+
+static int denali_dev_ready(struct mtd_info *mtd)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+
+	return !!(denali_check_irq(denali) & INTR__INT_ACT);
+}
+
 /*
  * sends a pipeline command operation to the controller. See the Denali NAND
  * controller's user guide for more information (section 4.2.3.6).
@@ -824,7 +856,13 @@ static void denali_select_chip(struct mtd_info *mtd, int chip)
 
 static int denali_waitfunc(struct mtd_info *mtd, struct nand_chip *chip)
 {
-	return 0;
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	uint32_t irq_status;
+
+	/* R/B# pin transitioned from low to high? */
+	irq_status = denali_wait_for_irq(denali, INTR__INT_ACT);
+
+	return irq_status & INTR__INT_ACT ? 0 : NAND_STATUS_FAIL;
 }
 
 static int denali_erase(struct mtd_info *mtd, int page)
@@ -845,46 +883,6 @@ static int denali_erase(struct mtd_info *mtd, int page)
 	return irq_status & INTR__ERASE_COMP ? 0 : NAND_STATUS_FAIL;
 }
 
-static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
-			   int page)
-{
-	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	uint32_t addr, irq_status;
-	int wait_ready = 0;
-
-	switch (cmd) {
-	case NAND_CMD_PARAM:
-		wait_ready = 1;
-		break;
-	case NAND_CMD_STATUS:
-	case NAND_CMD_READID:
-		break;
-	case NAND_CMD_RESET:
-		reset_bank(denali);
-		break;
-	case NAND_CMD_READOOB:
-		/* TODO: Read OOB data */
-		return;
-	default:
-		pr_err(": unsupported command received 0x%x\n", cmd);
-		return;
-	}
-
-	denali_reset_irq(denali);
-
-	addr = MODE_11 | BANK(denali->flash_bank);
-	index_addr(denali, addr | 0, cmd);
-	if (col != -1)
-		index_addr(denali, addr | 1, col);
-
-	if (!wait_ready)
-		return;
-
-	irq_status = denali_wait_for_irq(denali, INTR__INT_ACT);
-	if (!(irq_status & INTR__INT_ACT))
-		dev_err(denali->dev, "failed to issue command 0x%x\n", cmd);
-}
-
 #define DIV_ROUND_DOWN_ULL(ll, d) \
 	({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
 
@@ -1224,8 +1222,10 @@ int denali_init(struct denali_nand_info *denali)
 
 	/* register the driver with the NAND core subsystem */
 	chip->select_chip = denali_select_chip;
-	chip->cmdfunc = denali_cmdfunc;
 	chip->read_byte = denali_read_byte;
+	chip->write_byte = denali_write_byte;
+	chip->cmd_ctrl = denali_cmd_ctrl;
+	chip->dev_ready = denali_dev_ready;
 	chip->waitfunc = denali_waitfunc;
 	/* clk rate info is needed for setup_data_interface */
 	if (denali->clk_x_rate)
-- 
2.7.4

[PATCH v5 14/23] mtd: nand: denali: fix bank reset function to detect the number of chips

[Masahiro Yamada]

The nand_scan_ident() iterates over maxchips, and calls nand_reset()
for each.  This driver currently passes the maximum number of banks
(=chip selects) supported by the controller as maxchips.  So, maxchips
is typically 4 or 8.  Usually, less number of NAND chips are connected
to the controller.

This can be a problem for ONFi devices.  Now, this driver implements
->setup_data_interface() hook, so nand_setup_data_interface() issues
Set Features (0xEF) command, which waits until the chip returns R/B#
response.  If no chip there, we know it never happens, but the driver
still ends up with waiting for a long time.  It will finally bail-out
with timeout error and the driver will work with existing chips, but
unnecessary wait will give a bad user experience.

The denali_nand_reset() polls the INTR__RST_COMP and INTR__TIME_OUT
bits, but they are always set even if not NAND chip is connected to
that bank.  To know the chip existence, INTR__INT_ACT bit must be
checked; this flag is set only when R/B# is toggled.  Since the Reset
(0xFF) command toggles the R/B# pin, this can be used to know the
actual number of chips, and update denali->max_banks.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Boris mentioned this information can be retrieved from DT
(http://patchwork.ozlabs.org/patch/745118/), but I'd like to
take time for controller/chip decoupling.  I am tackling on
that, but not completed yet.

I believe this commit stands for denali_pci, at least I do not
know how to get the number of chips from PCI.


Changes in v5: None
Changes in v4:
  - Reword commit-log

Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 52 +++++++++++++++++++++--------------------------
 1 file changed, 23 insertions(+), 29 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 95bce6b341d7..8e2399ddfe3f 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -85,33 +85,6 @@ static void index_addr(struct denali_nand_info *denali,
 	iowrite32(data, denali->flash_mem + 0x10);
 }
 
-/* Reset the flash controller */
-static uint16_t denali_nand_reset(struct denali_nand_info *denali)
-{
-	int i;
-
-	for (i = 0; i < denali->max_banks; i++)
-		iowrite32(INTR__RST_COMP | INTR__TIME_OUT,
-		denali->flash_reg + INTR_STATUS(i));
-
-	for (i = 0; i < denali->max_banks; i++) {
-		iowrite32(1 << i, denali->flash_reg + DEVICE_RESET);
-		while (!(ioread32(denali->flash_reg + INTR_STATUS(i)) &
-			(INTR__RST_COMP | INTR__TIME_OUT)))
-			cpu_relax();
-		if (ioread32(denali->flash_reg + INTR_STATUS(i)) &
-			INTR__TIME_OUT)
-			dev_dbg(denali->dev,
-			"NAND Reset operation timed out on bank %d\n", i);
-	}
-
-	for (i = 0; i < denali->max_banks; i++)
-		iowrite32(INTR__RST_COMP | INTR__TIME_OUT,
-			  denali->flash_reg + INTR_STATUS(i));
-
-	return PASS;
-}
-
 /*
  * Use the configuration feature register to determine the maximum number of
  * banks that the hardware supports.
@@ -999,7 +972,28 @@ static int denali_setup_data_interface(struct mtd_info *mtd,
 	return 0;
 }
 
-/* Initialization code to bring the device up to a known good state */
+static void denali_reset_banks(struct denali_nand_info *denali)
+{
+	int i;
+
+	denali_clear_irq_all(denali);
+
+	for (i = 0; i < denali->max_banks; i++) {
+		iowrite32(1 << i, denali->flash_reg + DEVICE_RESET);
+		while (!(ioread32(denali->flash_reg + INTR_STATUS(i)) &
+			(INTR__RST_COMP | INTR__TIME_OUT)))
+			cpu_relax();
+		if (!(ioread32(denali->flash_reg + INTR_STATUS(i)) &
+		      INTR__INT_ACT))
+			break;
+	}
+
+	dev_dbg(denali->dev, "%d chips connected\n", i);
+	denali->max_banks = i;
+
+	denali_clear_irq_all(denali);
+}
+
 static void denali_hw_init(struct denali_nand_info *denali)
 {
 	/*
@@ -1019,7 +1013,7 @@ static void denali_hw_init(struct denali_nand_info *denali)
 	denali->bbtskipbytes = ioread32(denali->flash_reg +
 						SPARE_AREA_SKIP_BYTES);
 	detect_max_banks(denali);
-	denali_nand_reset(denali);
+	denali_reset_banks(denali);
 	iowrite32(0x0F, denali->flash_reg + RB_PIN_ENABLED);
 	iowrite32(CHIP_EN_DONT_CARE__FLAG,
 			denali->flash_reg + CHIP_ENABLE_DONT_CARE);
-- 
2.7.4

[PATCH v5 15/23] mtd: nand: denali: use interrupt instead of polling for bank reset

[Masahiro Yamada]

The current bank reset implementation polls the INTR_STATUS register
until interested bits are set.  This is not good because:

- polling simply wastes time-slice of the thread

- The while() loop may continue eternally if no bit is set, for
  example, due to the controller problem.  The denali_wait_for_irq()
  uses wait_for_completion_timeout(), which is safer.

We can use interrupt by moving the denali_reset_bank() call below
the interrupt setup.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 8e2399ddfe3f..eda206851a4b 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -974,24 +974,25 @@ static int denali_setup_data_interface(struct mtd_info *mtd,
 
 static void denali_reset_banks(struct denali_nand_info *denali)
 {
+	u32 irq_status;
 	int i;
 
-	denali_clear_irq_all(denali);
-
 	for (i = 0; i < denali->max_banks; i++) {
-		iowrite32(1 << i, denali->flash_reg + DEVICE_RESET);
-		while (!(ioread32(denali->flash_reg + INTR_STATUS(i)) &
-			(INTR__RST_COMP | INTR__TIME_OUT)))
-			cpu_relax();
-		if (!(ioread32(denali->flash_reg + INTR_STATUS(i)) &
-		      INTR__INT_ACT))
+		denali->flash_bank = i;
+
+		denali_reset_irq(denali);
+
+		iowrite32(DEVICE_RESET__BANK(i),
+			  denali->flash_reg + DEVICE_RESET);
+
+		irq_status = denali_wait_for_irq(denali,
+			INTR__RST_COMP | INTR__INT_ACT | INTR__TIME_OUT);
+		if (!(irq_status & INTR__INT_ACT))
 			break;
 	}
 
 	dev_dbg(denali->dev, "%d chips connected\n", i);
 	denali->max_banks = i;
-
-	denali_clear_irq_all(denali);
 }
 
 static void denali_hw_init(struct denali_nand_info *denali)
@@ -1013,7 +1014,6 @@ static void denali_hw_init(struct denali_nand_info *denali)
 	denali->bbtskipbytes = ioread32(denali->flash_reg +
 						SPARE_AREA_SKIP_BYTES);
 	detect_max_banks(denali);
-	denali_reset_banks(denali);
 	iowrite32(0x0F, denali->flash_reg + RB_PIN_ENABLED);
 	iowrite32(CHIP_EN_DONT_CARE__FLAG,
 			denali->flash_reg + CHIP_ENABLE_DONT_CARE);
@@ -1131,9 +1131,6 @@ static void denali_drv_init(struct denali_nand_info *denali)
 	 * element that might be access shared data (interrupt status)
 	 */
 	spin_lock_init(&denali->irq_lock);
-
-	/* indicate that MTD has not selected a valid bank yet */
-	denali->flash_bank = CHIP_SELECT_INVALID;
 }
 
 static int denali_multidev_fixup(struct denali_nand_info *denali)
@@ -1208,6 +1205,9 @@ int denali_init(struct denali_nand_info *denali)
 	}
 
 	denali_enable_irq(denali);
+	denali_reset_banks(denali);
+
+	denali->flash_bank = CHIP_SELECT_INVALID;
 
 	nand_set_flash_node(chip, denali->dev->of_node);
 	/* Fallback to the default name if DT did not give "label" property */
-- 
2.7.4

[PATCH v5 16/23] mtd: nand: denali: propagate page to helpers via function argument

[Masahiro Yamada]

This driver stores the currently addressed page into denali->page,
which is later read out by helper functions.  While I am tackling on
this driver, I often missed to insert "denali->page = page;" where
needed.  This makes page_read/write callbacks to get access to a
wrong page, which is a bug hard to figure out.

Instead, I'd rather pass the page via function argument because the
compiler's prototype checks will help to detect bugs.

For the same reason, propagate dma_addr to the DMA helpers instead
of denali->buf.dma_buf .

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 58 ++++++++++++++++++++---------------------------
 drivers/mtd/nand/denali.h |  1 -
 2 files changed, 24 insertions(+), 35 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index eda206851a4b..1a96942f62f9 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -282,7 +282,7 @@ static int denali_dev_ready(struct mtd_info *mtd)
  * sends a pipeline command operation to the controller. See the Denali NAND
  * controller's user guide for more information (section 4.2.3.6).
  */
-static int denali_send_pipeline_cmd(struct denali_nand_info *denali,
+static int denali_send_pipeline_cmd(struct denali_nand_info *denali, int page,
 				    bool ecc_en, bool transfer_spare,
 				    int access_type, int op)
 {
@@ -293,7 +293,7 @@ static int denali_send_pipeline_cmd(struct denali_nand_info *denali,
 
 	denali_reset_irq(denali);
 
-	addr = BANK(denali->flash_bank) | denali->page;
+	addr = BANK(denali->flash_bank) | page;
 
 	if (op == DENALI_WRITE && access_type != SPARE_ACCESS) {
 		cmd = MODE_01 | addr;
@@ -366,9 +366,7 @@ static int write_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 	uint32_t irq_mask = INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL;
 	int status = 0;
 
-	denali->page = page;
-
-	if (denali_send_pipeline_cmd(denali, false, false, SPARE_ACCESS,
+	if (denali_send_pipeline_cmd(denali, page, false, false, SPARE_ACCESS,
 							DENALI_WRITE) == PASS) {
 		write_data_to_flash_mem(denali, buf, mtd->oobsize);
 
@@ -393,9 +391,7 @@ static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 	uint32_t irq_mask = INTR__LOAD_COMP;
 	uint32_t irq_status, addr, cmd;
 
-	denali->page = page;
-
-	if (denali_send_pipeline_cmd(denali, false, true, SPARE_ACCESS,
+	if (denali_send_pipeline_cmd(denali, page, false, true, SPARE_ACCESS,
 							DENALI_READ) == PASS) {
 		read_data_from_flash_mem(denali, buf, mtd->oobsize);
 
@@ -407,8 +403,7 @@ static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 		irq_status = denali_wait_for_irq(denali, irq_mask);
 
 		if (!(irq_status & INTR__LOAD_COMP))
-			dev_err(denali->dev, "page on OOB timeout %d\n",
-					denali->page);
+			dev_err(denali->dev, "page on OOB timeout %d\n", page);
 
 		/*
 		 * We set the device back to MAIN_ACCESS here as I observed
@@ -417,7 +412,7 @@ static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 		 * is reliable (according to the MTD test infrastructure)
 		 * if you are in MAIN_ACCESS.
 		 */
-		addr = BANK(denali->flash_bank) | denali->page;
+		addr = BANK(denali->flash_bank) | page;
 		cmd = MODE_10 | addr;
 		index_addr(denali, cmd, MAIN_ACCESS);
 	}
@@ -582,13 +577,13 @@ static void denali_enable_dma(struct denali_nand_info *denali, bool en)
 	ioread32(denali->flash_reg + DMA_ENABLE);
 }
 
-static void denali_setup_dma64(struct denali_nand_info *denali, int op)
+static void denali_setup_dma64(struct denali_nand_info *denali,
+			       dma_addr_t dma_addr, int page, int op)
 {
 	uint32_t mode;
 	const int page_count = 1;
-	uint64_t addr = denali->buf.dma_buf;
 
-	mode = MODE_10 | BANK(denali->flash_bank) | denali->page;
+	mode = MODE_10 | BANK(denali->flash_bank) | page;
 
 	/* DMA is a three step process */
 
@@ -599,41 +594,42 @@ static void denali_setup_dma64(struct denali_nand_info *denali, int op)
 	index_addr(denali, mode, 0x01002000 | (64 << 16) | op | page_count);
 
 	/* 2. set memory low address */
-	index_addr(denali, mode, addr);
+	index_addr(denali, mode, dma_addr);
 
 	/* 3. set memory high address */
-	index_addr(denali, mode, addr >> 32);
+	index_addr(denali, mode, (uint64_t)dma_addr >> 32);
 }
 
-static void denali_setup_dma32(struct denali_nand_info *denali, int op)
+static void denali_setup_dma32(struct denali_nand_info *denali,
+			       dma_addr_t dma_addr, int page, int op)
 {
 	uint32_t mode;
 	const int page_count = 1;
-	uint32_t addr = denali->buf.dma_buf;
 
 	mode = MODE_10 | BANK(denali->flash_bank);
 
 	/* DMA is a four step process */
 
 	/* 1. setup transfer type and # of pages */
-	index_addr(denali, mode | denali->page, 0x2000 | op | page_count);
+	index_addr(denali, mode | page, 0x2000 | op | page_count);
 
 	/* 2. set memory high address bits 23:8 */
-	index_addr(denali, mode | ((addr >> 16) << 8), 0x2200);
+	index_addr(denali, mode | ((dma_addr >> 16) << 8), 0x2200);
 
 	/* 3. set memory low address bits 23:8 */
-	index_addr(denali, mode | ((addr & 0xffff) << 8), 0x2300);
+	index_addr(denali, mode | ((dma_addr & 0xffff) << 8), 0x2300);
 
 	/* 4. interrupt when complete, burst len = 64 bytes */
 	index_addr(denali, mode | 0x14000, 0x2400);
 }
 
-static void denali_setup_dma(struct denali_nand_info *denali, int op)
+static void denali_setup_dma(struct denali_nand_info *denali,
+			     dma_addr_t dma_addr, int page, int op)
 {
 	if (denali->caps & DENALI_CAP_DMA_64BIT)
-		denali_setup_dma64(denali, op);
+		denali_setup_dma64(denali, dma_addr, page, op);
 	else
-		denali_setup_dma32(denali, op);
+		denali_setup_dma32(denali, dma_addr, page, op);
 }
 
 /*
@@ -650,8 +646,6 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
 	int ret = 0;
 
-	denali->page = page;
-
 	/*
 	 * if it is a raw xfer, we want to disable ecc and send the spare area.
 	 * !raw_xfer - enable ecc
@@ -674,7 +668,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	denali_reset_irq(denali);
 	denali_enable_dma(denali, true);
 
-	denali_setup_dma(denali, DENALI_WRITE);
+	denali_setup_dma(denali, addr, page, DENALI_WRITE);
 
 	/* wait for operation to complete */
 	irq_status = denali_wait_for_irq(denali, irq_mask);
@@ -750,15 +744,13 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 	unsigned long uncor_ecc_flags = 0;
 	int stat = 0;
 
-	denali->page = page;
-
 	setup_ecc_for_xfer(denali, true, false);
 
 	denali_enable_dma(denali, true);
 	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
 
 	denali_reset_irq(denali);
-	denali_setup_dma(denali, DENALI_READ);
+	denali_setup_dma(denali, addr, page, DENALI_READ);
 
 	/* wait for operation to complete */
 	irq_status = denali_wait_for_irq(denali, irq_mask);
@@ -777,7 +769,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 		return stat;
 
 	if (uncor_ecc_flags) {
-		read_oob_data(mtd, chip->oob_poi, denali->page);
+		read_oob_data(mtd, chip->oob_poi, page);
 
 		stat = denali_check_erased_page(mtd, chip, buf,
 						uncor_ecc_flags, stat);
@@ -795,15 +787,13 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	uint32_t irq_mask = INTR__DMA_CMD_COMP;
 	uint32_t irq_status;
 
-	denali->page = page;
-
 	setup_ecc_for_xfer(denali, false, true);
 	denali_enable_dma(denali, true);
 
 	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
 
 	denali_reset_irq(denali);
-	denali_setup_dma(denali, DENALI_READ);
+	denali_setup_dma(denali, addr, page, DENALI_READ);
 
 	/* wait for operation to complete */
 	irq_status = denali_wait_for_irq(denali, irq_mask);
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index a84d8784ee98..ad2223d179d0 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -316,7 +316,6 @@ struct denali_nand_info {
 	int flash_bank; /* currently selected chip */
 	struct nand_buf buf;
 	struct device *dev;
-	int page;
 	void __iomem *flash_reg;	/* Register Interface */
 	void __iomem *flash_mem;	/* Host Data/Command Interface */
 
-- 
2.7.4

[PATCH v5 17/23] mtd: nand: denali: merge struct nand_buf into struct denali_nand_info

[Masahiro Yamada]

Now struct nand_buf has only two members, so I see no reason for the
separation.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 29 ++++++++++++++---------------
 drivers/mtd/nand/denali.h |  8 ++------
 2 files changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 1a96942f62f9..d8d207125701 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -640,7 +640,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 			const uint8_t *buf, int page, bool raw_xfer)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	dma_addr_t addr = denali->buf.dma_buf;
+	dma_addr_t addr = denali->dma_addr;
 	size_t size = mtd->writesize + mtd->oobsize;
 	uint32_t irq_status;
 	uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
@@ -654,11 +654,11 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	setup_ecc_for_xfer(denali, !raw_xfer, raw_xfer);
 
 	/* copy buffer into DMA buffer */
-	memcpy(denali->buf.buf, buf, mtd->writesize);
+	memcpy(denali->buf, buf, mtd->writesize);
 
 	if (raw_xfer) {
 		/* transfer the data to the spare area */
-		memcpy(denali->buf.buf + mtd->writesize,
+		memcpy(denali->buf + mtd->writesize,
 			chip->oob_poi,
 			mtd->oobsize);
 	}
@@ -735,7 +735,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 			    uint8_t *buf, int oob_required, int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	dma_addr_t addr = denali->buf.dma_buf;
+	dma_addr_t addr = denali->dma_addr;
 	size_t size = mtd->writesize + mtd->oobsize;
 	uint32_t irq_status;
 	uint32_t irq_mask = denali->caps & DENALI_CAP_HW_ECC_FIXUP ?
@@ -757,7 +757,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 
 	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_FROM_DEVICE);
 
-	memcpy(buf, denali->buf.buf, mtd->writesize);
+	memcpy(buf, denali->buf, mtd->writesize);
 
 	if (denali->caps & DENALI_CAP_HW_ECC_FIXUP)
 		stat = denali_hw_ecc_fixup(mtd, denali, &uncor_ecc_flags);
@@ -782,7 +782,7 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 				uint8_t *buf, int oob_required, int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	dma_addr_t addr = denali->buf.dma_buf;
+	dma_addr_t addr = denali->dma_addr;
 	size_t size = mtd->writesize + mtd->oobsize;
 	uint32_t irq_mask = INTR__DMA_CMD_COMP;
 	uint32_t irq_status;
@@ -804,8 +804,8 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 
 	denali_enable_dma(denali, false);
 
-	memcpy(buf, denali->buf.buf, mtd->writesize);
-	memcpy(chip->oob_poi, denali->buf.buf + mtd->writesize, mtd->oobsize);
+	memcpy(buf, denali->buf, mtd->writesize);
+	memcpy(chip->oob_poi, denali->buf + mtd->writesize, mtd->oobsize);
 
 	return 0;
 }
@@ -1224,10 +1224,9 @@ int denali_init(struct denali_nand_info *denali)
 	if (ret)
 		goto disable_irq;
 
-	denali->buf.buf = devm_kzalloc(denali->dev,
-			     mtd->writesize + mtd->oobsize,
-			     GFP_KERNEL);
-	if (!denali->buf.buf) {
+	denali->buf = devm_kzalloc(denali->dev, mtd->writesize + mtd->oobsize,
+				   GFP_KERNEL);
+	if (!denali->buf) {
 		ret = -ENOMEM;
 		goto disable_irq;
 	}
@@ -1240,10 +1239,10 @@ int denali_init(struct denali_nand_info *denali)
 		goto disable_irq;
 	}
 
-	denali->buf.dma_buf = dma_map_single(denali->dev, denali->buf.buf,
+	denali->dma_addr = dma_map_single(denali->dev, denali->buf,
 			     mtd->writesize + mtd->oobsize,
 			     DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(denali->dev, denali->buf.dma_buf)) {
+	if (dma_mapping_error(denali->dev, denali->dma_addr)) {
 		dev_err(denali->dev, "Failed to map DMA buffer\n");
 		ret = -EIO;
 		goto disable_irq;
@@ -1337,7 +1336,7 @@ void denali_remove(struct denali_nand_info *denali)
 
 	nand_release(mtd);
 	denali_disable_irq(denali);
-	dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize,
+	dma_unmap_single(denali->dev, denali->dma_addr, bufsize,
 			 DMA_BIDIRECTIONAL);
 }
 EXPORT_SYMBOL(denali_remove);
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index ad2223d179d0..1b991d3016f8 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -305,16 +305,10 @@
 #define MODE_10    0x08000000
 #define MODE_11    0x0C000000
 
-struct nand_buf {
-	uint8_t *buf;
-	dma_addr_t dma_buf;
-};
-
 struct denali_nand_info {
 	struct nand_chip nand;
 	unsigned long clk_x_rate;	/* bus interface clock rate */
 	int flash_bank; /* currently selected chip */
-	struct nand_buf buf;
 	struct device *dev;
 	void __iomem *flash_reg;	/* Register Interface */
 	void __iomem *flash_mem;	/* Host Data/Command Interface */
@@ -326,6 +320,8 @@ struct denali_nand_info {
 	uint32_t irq_status;
 	int irq;
 
+	void *buf;
+	dma_addr_t dma_addr;
 	int devnum;	/* represent how many nands connected */
 	int bbtskipbytes;
 	int max_banks;
-- 
2.7.4

[PATCH v5 18/23] mtd: nand: denali: use flag instead of register macro for direction

[Masahiro Yamada]

It is not a good idea to re-use macros that represent a specific
register bit field for the transfer direction.

It is true that bit 8 indicates the direction for the MAP10 pipeline
operation and the data DMA operation, but this is not valid across
the IP.

Use a simple flag (write: 1, read: 0) for the direction.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index d8d207125701..735dcbdbb1b4 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -53,9 +53,6 @@ static inline struct denali_nand_info *mtd_to_denali(struct mtd_info *mtd)
 #define MAIN_ACCESS		0x42
 #define MAIN_SPARE_ACCESS	0x43
 
-#define DENALI_READ	0
-#define DENALI_WRITE	0x100
-
 #define DENALI_NR_BANKS		4
 
 /*
@@ -284,7 +281,7 @@ static int denali_dev_ready(struct mtd_info *mtd)
  */
 static int denali_send_pipeline_cmd(struct denali_nand_info *denali, int page,
 				    bool ecc_en, bool transfer_spare,
-				    int access_type, int op)
+				    int access_type, int write)
 {
 	int status = PASS;
 	uint32_t addr, cmd;
@@ -295,17 +292,17 @@ static int denali_send_pipeline_cmd(struct denali_nand_info *denali, int page,
 
 	addr = BANK(denali->flash_bank) | page;
 
-	if (op == DENALI_WRITE && access_type != SPARE_ACCESS) {
+	if (write && access_type != SPARE_ACCESS) {
 		cmd = MODE_01 | addr;
 		iowrite32(cmd, denali->flash_mem);
-	} else if (op == DENALI_WRITE && access_type == SPARE_ACCESS) {
+	} else if (write && access_type == SPARE_ACCESS) {
 		/* read spare area */
 		cmd = MODE_10 | addr;
 		index_addr(denali, cmd, access_type);
 
 		cmd = MODE_01 | addr;
 		iowrite32(cmd, denali->flash_mem);
-	} else if (op == DENALI_READ) {
+	} else {
 		/* setup page read request for access type */
 		cmd = MODE_10 | addr;
 		index_addr(denali, cmd, access_type);
@@ -367,7 +364,7 @@ static int write_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 	int status = 0;
 
 	if (denali_send_pipeline_cmd(denali, page, false, false, SPARE_ACCESS,
-							DENALI_WRITE) == PASS) {
+							1) == PASS) {
 		write_data_to_flash_mem(denali, buf, mtd->oobsize);
 
 		/* wait for operation to complete */
@@ -392,7 +389,7 @@ static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
 	uint32_t irq_status, addr, cmd;
 
 	if (denali_send_pipeline_cmd(denali, page, false, true, SPARE_ACCESS,
-							DENALI_READ) == PASS) {
+							0) == PASS) {
 		read_data_from_flash_mem(denali, buf, mtd->oobsize);
 
 		/*
@@ -578,7 +575,7 @@ static void denali_enable_dma(struct denali_nand_info *denali, bool en)
 }
 
 static void denali_setup_dma64(struct denali_nand_info *denali,
-			       dma_addr_t dma_addr, int page, int op)
+			       dma_addr_t dma_addr, int page, int write)
 {
 	uint32_t mode;
 	const int page_count = 1;
@@ -591,7 +588,8 @@ static void denali_setup_dma64(struct denali_nand_info *denali,
 	 * 1. setup transfer type, interrupt when complete,
 	 *    burst len = 64 bytes, the number of pages
 	 */
-	index_addr(denali, mode, 0x01002000 | (64 << 16) | op | page_count);
+	index_addr(denali, mode,
+		   0x01002000 | (64 << 16) | (write << 8) | page_count);
 
 	/* 2. set memory low address */
 	index_addr(denali, mode, dma_addr);
@@ -601,7 +599,7 @@ static void denali_setup_dma64(struct denali_nand_info *denali,
 }
 
 static void denali_setup_dma32(struct denali_nand_info *denali,
-			       dma_addr_t dma_addr, int page, int op)
+			       dma_addr_t dma_addr, int page, int write)
 {
 	uint32_t mode;
 	const int page_count = 1;
@@ -611,7 +609,7 @@ static void denali_setup_dma32(struct denali_nand_info *denali,
 	/* DMA is a four step process */
 
 	/* 1. setup transfer type and # of pages */
-	index_addr(denali, mode | page, 0x2000 | op | page_count);
+	index_addr(denali, mode | page, 0x2000 | (write << 8) | page_count);
 
 	/* 2. set memory high address bits 23:8 */
 	index_addr(denali, mode | ((dma_addr >> 16) << 8), 0x2200);
@@ -624,12 +622,12 @@ static void denali_setup_dma32(struct denali_nand_info *denali,
 }
 
 static void denali_setup_dma(struct denali_nand_info *denali,
-			     dma_addr_t dma_addr, int page, int op)
+			     dma_addr_t dma_addr, int page, int write)
 {
 	if (denali->caps & DENALI_CAP_DMA_64BIT)
-		denali_setup_dma64(denali, dma_addr, page, op);
+		denali_setup_dma64(denali, dma_addr, page, write);
 	else
-		denali_setup_dma32(denali, dma_addr, page, op);
+		denali_setup_dma32(denali, dma_addr, page, write);
 }
 
 /*
@@ -668,7 +666,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
 	denali_reset_irq(denali);
 	denali_enable_dma(denali, true);
 
-	denali_setup_dma(denali, addr, page, DENALI_WRITE);
+	denali_setup_dma(denali, addr, page, 1);
 
 	/* wait for operation to complete */
 	irq_status = denali_wait_for_irq(denali, irq_mask);
@@ -750,7 +748,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
 
 	denali_reset_irq(denali);
-	denali_setup_dma(denali, addr, page, DENALI_READ);
+	denali_setup_dma(denali, addr, page, 0);
 
 	/* wait for operation to complete */
 	irq_status = denali_wait_for_irq(denali, irq_mask);
@@ -793,7 +791,7 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
 
 	denali_reset_irq(denali);
-	denali_setup_dma(denali, addr, page, DENALI_READ);
+	denali_setup_dma(denali, addr, page, 0);
 
 	/* wait for operation to complete */
 	irq_status = denali_wait_for_irq(denali, irq_mask);
-- 
2.7.4

[PATCH v5 19/23] mtd: nand: denali: fix raw and oob accessors for syndrome page layout

[Masahiro Yamada]

The Denali IP adopts the syndrome page layout; payload and ECC are
interleaved, with BBM area always placed at the beginning of OOB.

The figure below shows the page organization for ecc->steps == 2:

  |----------------|    |-----------|
  |                |    |           |
  |                |    |           |
  |    Payload0    |    |           |
  |                |    |           |
  |                |    |           |
  |                |    |           |
  |----------------|    |  in-band  |
  |      ECC0      |    |   area    |
  |----------------|    |           |
  |                |    |           |
  |                |    |           |
  |    Payload1    |    |           |
  |                |    |           |
  |                |    |           |
  |----------------|    |-----------|
  |      BBM       |    |           |
  |----------------|    |           |
  |Payload1 (cont.)|    |           |
  |----------------|    |out-of-band|
  |      ECC1      |    |    area   |
  |----------------|    |           |
  |    OOB free    |    |           |
  |----------------|    |-----------|

The current raw / oob accessors do not take that into consideration,
so in-band and out-of-band data are transferred as stored in the
device.  In the case above,

  in-band:      Payload0 + ECC0 + Payload1(partial)
  out-of-band:  BBM + Payload1(cont.) + ECC1 + OOB-free

This is wrong.  As the comment block of struct nand_ecc_ctrl says,
driver callbacks must hide the specific layout used by the hardware
and always return contiguous in-band and out-of-band data.

The current implementation is completely screwed-up, so read/write
callbacks must be re-worked.

Also, it is reasonable to support PIO transfer in case DMA may not
work for some reasons.  Actually, the Data DMA may not be equipped
depending on the configuration of the RTL.  This can be checked by
reading the bit 4 of the FEATURES register.  Even if the controller
has the DMA support, dma_set_mask() and dma_map_single() could fail.
In either case, the driver can fall back to the PIO transfer.  Slower
access would be better than giving up.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 613 ++++++++++++++++++++++++++++++----------------
 drivers/mtd/nand/denali.h |   3 +-
 2 files changed, 397 insertions(+), 219 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 735dcbdbb1b4..dcadf9655d7a 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -246,6 +246,53 @@ static void denali_write_byte(struct mtd_info *mtd, uint8_t byte)
 	index_addr(denali, MODE_11 | BANK(denali->flash_bank) | 2, byte);
 }
 
+static void denali_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	int i;
+
+	iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);
+
+	for (i = 0; i < len; i++)
+		buf[i] = ioread32(denali->flash_mem + 0x10);
+}
+
+static void denali_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	int i;
+
+	iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);
+
+	for (i = 0; i < len; i++)
+		iowrite32(buf[i], denali->flash_mem + 0x10);
+}
+
+static void denali_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	uint16_t *buf16 = (uint16_t *)buf;
+	int i;
+
+	iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);
+
+	for (i = 0; i < len / 2; i++)
+		buf16[i] = ioread32(denali->flash_mem + 0x10);
+}
+
+static void denali_write_buf16(struct mtd_info *mtd, const uint8_t *buf,
+			       int len)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	const uint16_t *buf16 = (const uint16_t *)buf;
+	int i;
+
+	iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);
+
+	for (i = 0; i < len / 2; i++)
+		iowrite32(buf16[i], denali->flash_mem + 0x10);
+}
+
 static void denali_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
@@ -275,44 +322,6 @@ static int denali_dev_ready(struct mtd_info *mtd)
 	return !!(denali_check_irq(denali) & INTR__INT_ACT);
 }
 
-/*
- * sends a pipeline command operation to the controller. See the Denali NAND
- * controller's user guide for more information (section 4.2.3.6).
- */
-static int denali_send_pipeline_cmd(struct denali_nand_info *denali, int page,
-				    bool ecc_en, bool transfer_spare,
-				    int access_type, int write)
-{
-	int status = PASS;
-	uint32_t addr, cmd;
-
-	setup_ecc_for_xfer(denali, ecc_en, transfer_spare);
-
-	denali_reset_irq(denali);
-
-	addr = BANK(denali->flash_bank) | page;
-
-	if (write && access_type != SPARE_ACCESS) {
-		cmd = MODE_01 | addr;
-		iowrite32(cmd, denali->flash_mem);
-	} else if (write && access_type == SPARE_ACCESS) {
-		/* read spare area */
-		cmd = MODE_10 | addr;
-		index_addr(denali, cmd, access_type);
-
-		cmd = MODE_01 | addr;
-		iowrite32(cmd, denali->flash_mem);
-	} else {
-		/* setup page read request for access type */
-		cmd = MODE_10 | addr;
-		index_addr(denali, cmd, access_type);
-
-		cmd = MODE_01 | addr;
-		iowrite32(cmd, denali->flash_mem);
-	}
-	return status;
-}
-
 /* helper function that simply writes a buffer to the flash */
 static int write_data_to_flash_mem(struct denali_nand_info *denali,
 				   const uint8_t *buf, int len)
@@ -355,66 +364,6 @@ static int read_data_from_flash_mem(struct denali_nand_info *denali,
 	return i * 4; /* intent is to return the number of bytes read */
 }
 
-/* writes OOB data to the device */
-static int write_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
-{
-	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	uint32_t irq_status;
-	uint32_t irq_mask = INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL;
-	int status = 0;
-
-	if (denali_send_pipeline_cmd(denali, page, false, false, SPARE_ACCESS,
-							1) == PASS) {
-		write_data_to_flash_mem(denali, buf, mtd->oobsize);
-
-		/* wait for operation to complete */
-		irq_status = denali_wait_for_irq(denali, irq_mask);
-
-		if (!(irq_status & INTR__PROGRAM_COMP)) {
-			dev_err(denali->dev, "OOB write failed\n");
-			status = -EIO;
-		}
-	} else {
-		dev_err(denali->dev, "unable to send pipeline command\n");
-		status = -EIO;
-	}
-	return status;
-}
-
-/* reads OOB data from the device */
-static void read_oob_data(struct mtd_info *mtd, uint8_t *buf, int page)
-{
-	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	uint32_t irq_mask = INTR__LOAD_COMP;
-	uint32_t irq_status, addr, cmd;
-
-	if (denali_send_pipeline_cmd(denali, page, false, true, SPARE_ACCESS,
-							0) == PASS) {
-		read_data_from_flash_mem(denali, buf, mtd->oobsize);
-
-		/*
-		 * wait for command to be accepted
-		 * can always use status0 bit as the
-		 * mask is identical for each bank.
-		 */
-		irq_status = denali_wait_for_irq(denali, irq_mask);
-
-		if (!(irq_status & INTR__LOAD_COMP))
-			dev_err(denali->dev, "page on OOB timeout %d\n", page);
-
-		/*
-		 * We set the device back to MAIN_ACCESS here as I observed
-		 * instability with the controller if you do a block erase
-		 * and the last transaction was a SPARE_ACCESS. Block erase
-		 * is reliable (according to the MTD test infrastructure)
-		 * if you are in MAIN_ACCESS.
-		 */
-		addr = BANK(denali->flash_bank) | page;
-		cmd = MODE_10 | addr;
-		index_addr(denali, cmd, MAIN_ACCESS);
-	}
-}
-
 static int denali_check_erased_page(struct mtd_info *mtd,
 				    struct nand_chip *chip, uint8_t *buf,
 				    unsigned long uncor_ecc_flags,
@@ -630,144 +579,302 @@ static void denali_setup_dma(struct denali_nand_info *denali,
 		denali_setup_dma32(denali, dma_addr, page, write);
 }
 
-/*
- * writes a page. user specifies type, and this function handles the
- * configuration details.
- */
-static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
-			const uint8_t *buf, int page, bool raw_xfer)
+static int denali_pio_read(struct denali_nand_info *denali, void *buf,
+			   size_t size, int page, int raw)
 {
-	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	dma_addr_t addr = denali->dma_addr;
-	size_t size = mtd->writesize + mtd->oobsize;
-	uint32_t irq_status;
-	uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
-	int ret = 0;
+	uint32_t addr = BANK(denali->flash_bank) | page;
+	uint32_t irq_status, ecc_err_mask;
 
-	/*
-	 * if it is a raw xfer, we want to disable ecc and send the spare area.
-	 * !raw_xfer - enable ecc
-	 * raw_xfer - transfer spare
-	 */
-	setup_ecc_for_xfer(denali, !raw_xfer, raw_xfer);
+	/* setup page read request for access type */
+	index_addr(denali, MODE_10 | addr,
+		   raw ? MAIN_SPARE_ACCESS : MAIN_ACCESS);
 
-	/* copy buffer into DMA buffer */
-	memcpy(denali->buf, buf, mtd->writesize);
+	iowrite32(MODE_01 | addr, denali->flash_mem);
 
-	if (raw_xfer) {
-		/* transfer the data to the spare area */
-		memcpy(denali->buf + mtd->writesize,
-			chip->oob_poi,
-			mtd->oobsize);
-	}
+	if (denali->caps & DENALI_CAP_HW_ECC_FIXUP)
+		ecc_err_mask = INTR__ECC_UNCOR_ERR;
+	else
+		ecc_err_mask = INTR__ECC_ERR;
 
-	dma_sync_single_for_device(denali->dev, addr, size, DMA_TO_DEVICE);
+	denali_reset_irq(denali);
+
+	read_data_from_flash_mem(denali, buf, size);
+
+	irq_status = denali_wait_for_irq(denali, INTR__PAGE_XFER_INC);
+	if (!(irq_status & INTR__PAGE_XFER_INC))
+		return -EIO;
+
+	return irq_status & ecc_err_mask ? -EBADMSG : 0;
+}
+
+static int denali_pio_write(struct denali_nand_info *denali,
+			    const void *buf, size_t size, int page, int raw)
+{
+	uint32_t addr = BANK(denali->flash_bank) | page;
+	uint32_t irq_status;
+
+	/* setup page read request for access type */
+	index_addr(denali, MODE_10 | addr,
+		   raw ? MAIN_SPARE_ACCESS : MAIN_ACCESS);
+
+	iowrite32(MODE_01 | addr, denali->flash_mem);
 
 	denali_reset_irq(denali);
+
+	write_data_to_flash_mem(denali, buf, size);
+
+	irq_status = denali_wait_for_irq(denali,
+				INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL);
+	if (!(irq_status & INTR__PROGRAM_COMP))
+		return -EIO;
+
+	return 0;
+}
+
+static int denali_pio_xfer(struct denali_nand_info *denali, void *buf,
+			   size_t size, int page, int raw, int write)
+{
+	if (write)
+		return denali_pio_write(denali, buf, size, page, raw);
+	else
+		return denali_pio_read(denali, buf, size, page, raw);
+}
+
+static int denali_dma_xfer(struct denali_nand_info *denali, void *buf,
+			   size_t size, int page, int raw, int write)
+{
+	dma_addr_t dma_addr = denali->dma_addr;
+	uint32_t irq_mask, irq_status, ecc_err_mask;
+	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+	int ret = 0;
+
+	dma_sync_single_for_device(denali->dev, dma_addr, size, dir);
+
+	if (write) {
+		irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
+		ecc_err_mask = 0;
+	} else if (denali->caps & DENALI_CAP_HW_ECC_FIXUP) {
+		irq_mask = INTR__DMA_CMD_COMP;
+		ecc_err_mask = INTR__ECC_UNCOR_ERR;
+	} else {
+		irq_mask = INTR__DMA_CMD_COMP;
+		ecc_err_mask = INTR__ECC_ERR;
+	}
+
 	denali_enable_dma(denali, true);
 
-	denali_setup_dma(denali, addr, page, 1);
+	denali_reset_irq(denali);
+	denali_setup_dma(denali, dma_addr, page, write);
 
 	/* wait for operation to complete */
 	irq_status = denali_wait_for_irq(denali, irq_mask);
-	if (!(irq_status & INTR__DMA_CMD_COMP)) {
-		dev_err(denali->dev, "timeout on write_page (type = %d)\n",
-			raw_xfer);
+	if (!(irq_status & INTR__DMA_CMD_COMP))
 		ret = -EIO;
-	}
+	else if (irq_status & ecc_err_mask)
+		ret = -EBADMSG;
 
 	denali_enable_dma(denali, false);
-	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_TO_DEVICE);
+	dma_sync_single_for_cpu(denali->dev, dma_addr, size, dir);
 
 	return ret;
 }
 
-/* NAND core entry points */
-
-/*
- * this is the callback that the NAND core calls to write a page. Since
- * writing a page with ECC or without is similar, all the work is done
- * by write_page above.
- */
-static int denali_write_page(struct mtd_info *mtd, struct nand_chip *chip,
-				const uint8_t *buf, int oob_required, int page)
+static int denali_data_xfer(struct denali_nand_info *denali, void *buf,
+			    size_t size, int page, int raw, int write)
 {
-	/*
-	 * for regular page writes, we let HW handle all the ECC
-	 * data written to the device.
-	 */
-	return write_page(mtd, chip, buf, page, false);
+	setup_ecc_for_xfer(denali, !raw, raw);
+
+	if (denali->dma_avail)
+		return denali_dma_xfer(denali, buf, size, page, raw, write);
+	else
+		return denali_pio_xfer(denali, buf, size, page, raw, write);
 }
 
-/*
- * This is the callback that the NAND core calls to write a page without ECC.
- * raw access is similar to ECC page writes, so all the work is done in the
- * write_page() function above.
- */
-static int denali_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
-				 const uint8_t *buf, int oob_required,
-				 int page)
+static void denali_oob_xfer(struct mtd_info *mtd, struct nand_chip *chip,
+			    int page, int write)
 {
-	/*
-	 * for raw page writes, we want to disable ECC and simply write
-	 * whatever data is in the buffer.
-	 */
-	return write_page(mtd, chip, buf, page, true);
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	unsigned int start_cmd = write ? NAND_CMD_SEQIN : NAND_CMD_READ0;
+	unsigned int rnd_cmd = write ? NAND_CMD_RNDIN : NAND_CMD_RNDOUT;
+	int writesize = mtd->writesize;
+	int oobsize = mtd->oobsize;
+	uint8_t *bufpoi = chip->oob_poi;
+	int ecc_steps = chip->ecc.steps;
+	int ecc_size = chip->ecc.size;
+	int ecc_bytes = chip->ecc.bytes;
+	int oob_skip = denali->bbtskipbytes;
+	size_t size = writesize + oobsize;
+	int i, pos, len;
+
+	/* BBM at the beginning of the OOB area */
+	chip->cmdfunc(mtd, start_cmd, writesize, page);
+	if (write)
+		chip->write_buf(mtd, bufpoi, oob_skip);
+	else
+		chip->read_buf(mtd, bufpoi, oob_skip);
+	bufpoi += oob_skip;
+
+	/* OOB ECC */
+	for (i = 0; i < ecc_steps; i++) {
+		pos = ecc_size + i * (ecc_size + ecc_bytes);
+		len = ecc_bytes;
+
+		if (pos >= writesize)
+			pos += oob_skip;
+		else if (pos + len > writesize)
+			len = writesize - pos;
+
+		chip->cmdfunc(mtd, rnd_cmd, pos, -1);
+		if (write)
+			chip->write_buf(mtd, bufpoi, len);
+		else
+			chip->read_buf(mtd, bufpoi, len);
+		bufpoi += len;
+		if (len < ecc_bytes) {
+			len = ecc_bytes - len;
+			chip->cmdfunc(mtd, rnd_cmd, writesize + oob_skip, -1);
+			if (write)
+				chip->write_buf(mtd, bufpoi, len);
+			else
+				chip->read_buf(mtd, bufpoi, len);
+			bufpoi += len;
+		}
+	}
+
+	/* OOB free */
+	len = oobsize - (bufpoi - chip->oob_poi);
+	chip->cmdfunc(mtd, rnd_cmd, size - len, -1);
+	if (write)
+		chip->write_buf(mtd, bufpoi, len);
+	else
+		chip->read_buf(mtd, bufpoi, len);
 }
 
-static int denali_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
-			    int page)
+static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+				uint8_t *buf, int oob_required, int page)
 {
-	return write_oob_data(mtd, chip->oob_poi, page);
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	int writesize = mtd->writesize;
+	int oobsize = mtd->oobsize;
+	int ecc_steps = chip->ecc.steps;
+	int ecc_size = chip->ecc.size;
+	int ecc_bytes = chip->ecc.bytes;
+	void *dma_buf = denali->buf;
+	int oob_skip = denali->bbtskipbytes;
+	size_t size = writesize + oobsize;
+	int ret, i, pos, len;
+
+	ret = denali_data_xfer(denali, dma_buf, size, page, 1, 0);
+	if (ret)
+		return ret;
+
+	/* Arrange the buffer for syndrome payload/ecc layout */
+	if (buf) {
+		for (i = 0; i < ecc_steps; i++) {
+			pos = i * (ecc_size + ecc_bytes);
+			len = ecc_size;
+
+			if (pos >= writesize)
+				pos += oob_skip;
+			else if (pos + len > writesize)
+				len = writesize - pos;
+
+			memcpy(buf, dma_buf + pos, len);
+			buf += len;
+			if (len < ecc_size) {
+				len = ecc_size - len;
+				memcpy(buf, dma_buf + writesize + oob_skip,
+				       len);
+				buf += len;
+			}
+		}
+	}
+
+	if (oob_required) {
+		uint8_t *oob = chip->oob_poi;
+
+		/* BBM at the beginning of the OOB area */
+		memcpy(oob, dma_buf + writesize, oob_skip);
+		oob += oob_skip;
+
+		/* OOB ECC */
+		for (i = 0; i < ecc_steps; i++) {
+			pos = ecc_size + i * (ecc_size + ecc_bytes);
+			len = ecc_bytes;
+
+			if (pos >= writesize)
+				pos += oob_skip;
+			else if (pos + len > writesize)
+				len = writesize - pos;
+
+			memcpy(oob, dma_buf + pos, len);
+			oob += len;
+			if (len < ecc_bytes) {
+				len = ecc_bytes - len;
+				memcpy(oob, dma_buf + writesize + oob_skip,
+				       len);
+				oob += len;
+			}
+		}
+
+		/* OOB free */
+		len = oobsize - (oob - chip->oob_poi);
+		memcpy(oob, dma_buf + size - len, len);
+	}
+
+	return 0;
 }
 
 static int denali_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
 			   int page)
 {
-	read_oob_data(mtd, chip->oob_poi, page);
+	denali_oob_xfer(mtd, chip, page, 0);
 
 	return 0;
 }
 
-static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
-			    uint8_t *buf, int oob_required, int page)
+static int denali_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
+			    int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	dma_addr_t addr = denali->dma_addr;
-	size_t size = mtd->writesize + mtd->oobsize;
-	uint32_t irq_status;
-	uint32_t irq_mask = denali->caps & DENALI_CAP_HW_ECC_FIXUP ?
-				INTR__DMA_CMD_COMP | INTR__ECC_UNCOR_ERR :
-				INTR__ECC_TRANSACTION_DONE | INTR__ECC_ERR;
-	unsigned long uncor_ecc_flags = 0;
-	int stat = 0;
+	int status;
 
-	setup_ecc_for_xfer(denali, true, false);
+	denali_reset_irq(denali);
 
-	denali_enable_dma(denali, true);
-	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
+	denali_oob_xfer(mtd, chip, page, 1);
 
-	denali_reset_irq(denali);
-	denali_setup_dma(denali, addr, page, 0);
+	chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+	status = chip->waitfunc(mtd, chip);
 
-	/* wait for operation to complete */
-	irq_status = denali_wait_for_irq(denali, irq_mask);
+	return status & NAND_STATUS_FAIL ? -EIO : 0;
+}
 
-	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_FROM_DEVICE);
+static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
+			    uint8_t *buf, int oob_required, int page)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
+	unsigned long uncor_ecc_flags = 0;
+	int stat = 0;
+	int ret;
+
+	ret = denali_data_xfer(denali, denali->buf, mtd->writesize, page, 0, 0);
+	if (ret && ret != -EBADMSG)
+		return ret;
 
 	memcpy(buf, denali->buf, mtd->writesize);
 
 	if (denali->caps & DENALI_CAP_HW_ECC_FIXUP)
 		stat = denali_hw_ecc_fixup(mtd, denali, &uncor_ecc_flags);
-	else if (irq_status & INTR__ECC_ERR)
+	else if (ret == -EBADMSG)
 		stat = denali_sw_ecc_fixup(mtd, denali, &uncor_ecc_flags, buf);
-	denali_enable_dma(denali, false);
 
 	if (stat < 0)
 		return stat;
 
 	if (uncor_ecc_flags) {
-		read_oob_data(mtd, chip->oob_poi, page);
+		ret = denali_read_oob(mtd, chip, page);
+		if (ret)
+			return ret;
 
 		stat = denali_check_erased_page(mtd, chip, buf,
 						uncor_ecc_flags, stat);
@@ -776,36 +883,93 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 	return stat;
 }
 
-static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
-				uint8_t *buf, int oob_required, int page)
+static int denali_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+				 const uint8_t *buf, int oob_required, int page)
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
-	dma_addr_t addr = denali->dma_addr;
-	size_t size = mtd->writesize + mtd->oobsize;
-	uint32_t irq_mask = INTR__DMA_CMD_COMP;
-	uint32_t irq_status;
-
-	setup_ecc_for_xfer(denali, false, true);
-	denali_enable_dma(denali, true);
+	int writesize = mtd->writesize;
+	int oobsize = mtd->oobsize;
+	int ecc_steps = chip->ecc.steps;
+	int ecc_size = chip->ecc.size;
+	int ecc_bytes = chip->ecc.bytes;
+	void *dma_buf = denali->buf;
+	int oob_skip = denali->bbtskipbytes;
+	size_t size = writesize + oobsize;
+	int i, pos, len;
 
-	dma_sync_single_for_device(denali->dev, addr, size, DMA_FROM_DEVICE);
+	/*
+	 * Fill the buffer with 0xff first except the full page transfer.
+	 * This simplifies the logic.
+	 */
+	if (!buf || !oob_required)
+		memset(dma_buf, 0xff, size);
+
+	/* Arrange the buffer for syndrome payload/ecc layout */
+	if (buf) {
+		for (i = 0; i < ecc_steps; i++) {
+			pos = i * (ecc_size + ecc_bytes);
+			len = ecc_size;
+
+			if (pos >= writesize)
+				pos += oob_skip;
+			else if (pos + len > writesize)
+				len = writesize - pos;
+
+			memcpy(dma_buf + pos, buf, len);
+			buf += len;
+			if (len < ecc_size) {
+				len = ecc_size - len;
+				memcpy(dma_buf + writesize + oob_skip, buf,
+				       len);
+				buf += len;
+			}
+		}
+	}
 
-	denali_reset_irq(denali);
-	denali_setup_dma(denali, addr, page, 0);
+	if (oob_required) {
+		const uint8_t *oob = chip->oob_poi;
+
+		/* BBM at the beginning of the OOB area */
+		memcpy(dma_buf + writesize, oob, oob_skip);
+		oob += oob_skip;
+
+		/* OOB ECC */
+		for (i = 0; i < ecc_steps; i++) {
+			pos = ecc_size + i * (ecc_size + ecc_bytes);
+			len = ecc_bytes;
+
+			if (pos >= writesize)
+				pos += oob_skip;
+			else if (pos + len > writesize)
+				len = writesize - pos;
+
+			memcpy(dma_buf + pos, oob, len);
+			oob += len;
+			if (len < ecc_bytes) {
+				len = ecc_bytes - len;
+				memcpy(dma_buf + writesize + oob_skip, oob,
+				       len);
+				oob += len;
+			}
+		}
 
-	/* wait for operation to complete */
-	irq_status = denali_wait_for_irq(denali, irq_mask);
-	if (irq_status & INTR__DMA_CMD_COMP)
-		return -ETIMEDOUT;
+		/* OOB free */
+		len = oobsize - (oob - chip->oob_poi);
+		memcpy(dma_buf + size - len, oob, len);
+	}
 
-	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_FROM_DEVICE);
+	return denali_data_xfer(denali, dma_buf, size, page, 1, 1);
+}
 
-	denali_enable_dma(denali, false);
+static int denali_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+			     const uint8_t *buf, int oob_required, int page)
+{
+	struct denali_nand_info *denali = mtd_to_denali(mtd);
 
-	memcpy(buf, denali->buf, mtd->writesize);
-	memcpy(chip->oob_poi, denali->buf + mtd->writesize, mtd->oobsize);
+	memcpy(denali->buf, buf, mtd->writesize);
 
-	return 0;
+	return denali_data_xfer(denali, denali->buf, mtd->writesize, page,
+				0, 1);
 }
 
 static void denali_select_chip(struct mtd_info *mtd, int chip)
@@ -1229,21 +1393,29 @@ int denali_init(struct denali_nand_info *denali)
 		goto disable_irq;
 	}
 
-	ret = dma_set_mask(denali->dev,
-			   DMA_BIT_MASK(denali->caps & DENALI_CAP_DMA_64BIT ?
-					64 : 32));
-	if (ret) {
-		dev_err(denali->dev, "No usable DMA configuration\n");
-		goto disable_irq;
+	if (ioread32(denali->flash_reg + FEATURES) & FEATURES__DMA)
+		denali->dma_avail = 1;
+
+	if (denali->dma_avail) {
+		int dma_bit = denali->caps & DENALI_CAP_DMA_64BIT ? 64 : 32;
+
+		ret = dma_set_mask(denali->dev, DMA_BIT_MASK(dma_bit));
+		if (ret) {
+			dev_info(denali->dev,
+				 "Failed to set DMA mask. Disabling DMA.\n");
+			denali->dma_avail = 0;
+		}
 	}
 
-	denali->dma_addr = dma_map_single(denali->dev, denali->buf,
-			     mtd->writesize + mtd->oobsize,
-			     DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(denali->dev, denali->dma_addr)) {
-		dev_err(denali->dev, "Failed to map DMA buffer\n");
-		ret = -EIO;
-		goto disable_irq;
+	if (denali->dma_avail) {
+		denali->dma_addr = dma_map_single(denali->dev, denali->buf,
+						  mtd->writesize + mtd->oobsize,
+						  DMA_BIDIRECTIONAL);
+		if (dma_mapping_error(denali->dev, denali->dma_addr)) {
+			dev_info(denali->dev,
+				 "Failed to map DMA buffer. Disabling DMA.\n");
+			denali->dma_avail = 0;
+		};
 	}
 
 	/*
@@ -1290,6 +1462,13 @@ int denali_init(struct denali_nand_info *denali)
 
 	mtd_set_ooblayout(mtd, &denali_ooblayout_ops);
 
+	if (chip->options & NAND_BUSWIDTH_16) {
+		chip->read_buf = denali_read_buf16;
+		chip->write_buf = denali_write_buf16;
+	} else {
+		chip->read_buf = denali_read_buf;
+		chip->write_buf = denali_write_buf;
+	}
 	chip->ecc.options |= NAND_ECC_CUSTOM_PAGE_ACCESS;
 	chip->ecc.read_page = denali_read_page;
 	chip->ecc.read_page_raw = denali_read_page_raw;
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 1b991d3016f8..f5da52f09e34 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -298,8 +298,6 @@
 #define     CHNL_ACTIVE__CHANNEL2			BIT(2)
 #define     CHNL_ACTIVE__CHANNEL3			BIT(3)
 
-#define PASS 0                  /*success flag*/
-
 #define MODE_00    0x00000000
 #define MODE_01    0x04000000
 #define MODE_10    0x08000000
@@ -322,6 +320,7 @@ struct denali_nand_info {
 
 	void *buf;
 	dma_addr_t dma_addr;
+	int dma_avail;
 	int devnum;	/* represent how many nands connected */
 	int bbtskipbytes;
 	int max_banks;
-- 
2.7.4

[PATCH v5 20/23] mtd: nand: denali: support hardware-assisted erased page detection

[Masahiro Yamada]

Recent versions of this IP support automatic erased page detection.
If an erased page is detected on reads, the controller does not set
INTR__ECC_UNCOR_ERR, but INTR__ERASED_PAGE.

The detection of erased page is based on the number of zeros in a
page; if the number of zeros is less than the value in the field
ERASED_THRESHOLD, the page is assumed as erased.

Please note ERASED_THRESHOLD specifies the number of zeros in a _page_
instead of an ECC chunk.  Moreover, the controller does not provide a
way to know the actual number of bitflips.

Actually, an erased page (all 0xff) is not an ECC correctable pattern
on the Denali ECC engine.  In other words, there is overlap between
the following two:

[1] a bit pattern reachable from a valid payload + ECC pattern within
    ecc.strength bitflips
[2] a bit pattern reachable from an erased state (all 0xff) within
    ecc.strength bitflips

So, this feature may intercept ECC correctable patterns, then replace
[1] with [2].

After all, this feature can work safely only when ECC_THRESHOLD == 1,
i.e. detect erased pages without any bitflips.  This should be the
case most of the time.  If there are some bitflips, the driver will
fallback to the software method by using nand_check_erased_ecc_chunk().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5:
  - Set ECC_THRESHOLD to 1

Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 3 ++-
 drivers/mtd/nand/denali.h | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index dcadf9655d7a..90c702b9f14c 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -1446,7 +1446,8 @@ int denali_init(struct denali_nand_info *denali)
 		"chosen ECC settings: step=%d, strength=%d, bytes=%d\n",
 		chip->ecc.size, chip->ecc.strength, chip->ecc.bytes);
 
-	iowrite32(chip->ecc.strength, denali->flash_reg + ECC_CORRECTION);
+	iowrite32(MAKE_ECC_CORRECTION(chip->ecc.strength, 1),
+		  denali->flash_reg + ECC_CORRECTION);
 	iowrite32(mtd->erasesize / mtd->writesize,
 		  denali->flash_reg + PAGES_PER_BLOCK);
 	iowrite32(chip->options & NAND_BUSWIDTH_16 ? 1 : 0,
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index f5da52f09e34..657a794af695 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -110,6 +110,10 @@
 
 #define ECC_CORRECTION				0x1b0
 #define     ECC_CORRECTION__VALUE			GENMASK(4, 0)
+#define     ECC_CORRECTION__ERASE_THRESHOLD		GENMASK(31, 16)
+#define     MAKE_ECC_CORRECTION(val, thresh)		\
+			(((val) & (ECC_CORRECTION__VALUE)) | \
+			(((thresh) << 16) & (ECC_CORRECTION__ERASE_THRESHOLD)))
 
 #define READ_MODE				0x1c0
 #define     READ_MODE__VALUE				GENMASK(3, 0)
@@ -233,6 +237,7 @@
 #define     INTR__RST_COMP				BIT(13)
 #define     INTR__PIPE_CMD_ERR				BIT(14)
 #define     INTR__PAGE_XFER_INC				BIT(15)
+#define     INTR__ERASED_PAGE				BIT(16)
 
 #define PAGE_CNT(bank)				(0x430 + (bank) * 0x50)
 #define ERR_PAGE_ADDR(bank)			(0x440 + (bank) * 0x50)
-- 
2.7.4

[PATCH v5 21/23] mtd: nand: denali: skip driver internal bounce buffer when possible

[Masahiro Yamada]

For ecc->read_page() and ecc->write_page(), it is possible to call
dma_map_single() against the given buffer.  This bypasses the driver
internal bounce buffer and save the memcpy().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4:
  - Remove dma_unmap_single() from denali_remove()

Changes in v3:
  - Set chip->buf_align to 16

Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 38 ++++++++++++--------------------------
 1 file changed, 12 insertions(+), 26 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 90c702b9f14c..963638693850 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -643,12 +643,16 @@ static int denali_pio_xfer(struct denali_nand_info *denali, void *buf,
 static int denali_dma_xfer(struct denali_nand_info *denali, void *buf,
 			   size_t size, int page, int raw, int write)
 {
-	dma_addr_t dma_addr = denali->dma_addr;
+	dma_addr_t dma_addr;
 	uint32_t irq_mask, irq_status, ecc_err_mask;
 	enum dma_data_direction dir = write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 	int ret = 0;
 
-	dma_sync_single_for_device(denali->dev, dma_addr, size, dir);
+	dma_addr = dma_map_single(denali->dev, buf, size, dir);
+	if (dma_mapping_error(denali->dev, dma_addr)) {
+		dev_dbg(denali->dev, "Failed to DMA-map buffer. Trying PIO.\n");
+		return denali_pio_xfer(denali, buf, size, page, raw, write);
+	}
 
 	if (write) {
 		irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
@@ -674,7 +678,7 @@ static int denali_dma_xfer(struct denali_nand_info *denali, void *buf,
 		ret = -EBADMSG;
 
 	denali_enable_dma(denali, false);
-	dma_sync_single_for_cpu(denali->dev, dma_addr, size, dir);
+	dma_unmap_single(denali->dev, dma_addr, size, dir);
 
 	return ret;
 }
@@ -857,12 +861,10 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 	int stat = 0;
 	int ret;
 
-	ret = denali_data_xfer(denali, denali->buf, mtd->writesize, page, 0, 0);
+	ret = denali_data_xfer(denali, buf, mtd->writesize, page, 0, 0);
 	if (ret && ret != -EBADMSG)
 		return ret;
 
-	memcpy(buf, denali->buf, mtd->writesize);
-
 	if (denali->caps & DENALI_CAP_HW_ECC_FIXUP)
 		stat = denali_hw_ecc_fixup(mtd, denali, &uncor_ecc_flags);
 	else if (ret == -EBADMSG)
@@ -966,10 +968,8 @@ static int denali_write_page(struct mtd_info *mtd, struct nand_chip *chip,
 {
 	struct denali_nand_info *denali = mtd_to_denali(mtd);
 
-	memcpy(denali->buf, buf, mtd->writesize);
-
-	return denali_data_xfer(denali, denali->buf, mtd->writesize, page,
-				0, 1);
+	return denali_data_xfer(denali, (void *)buf, mtd->writesize,
+				page, 0, 1);
 }
 
 static void denali_select_chip(struct mtd_info *mtd, int chip)
@@ -1408,14 +1408,8 @@ int denali_init(struct denali_nand_info *denali)
 	}
 
 	if (denali->dma_avail) {
-		denali->dma_addr = dma_map_single(denali->dev, denali->buf,
-						  mtd->writesize + mtd->oobsize,
-						  DMA_BIDIRECTIONAL);
-		if (dma_mapping_error(denali->dev, denali->dma_addr)) {
-			dev_info(denali->dev,
-				 "Failed to map DMA buffer. Disabling DMA.\n");
-			denali->dma_avail = 0;
-		};
+		chip->options |= NAND_USE_BOUNCE_BUFFER;
+		chip->buf_align = 16;
 	}
 
 	/*
@@ -1505,16 +1499,8 @@ EXPORT_SYMBOL(denali_init);
 void denali_remove(struct denali_nand_info *denali)
 {
 	struct mtd_info *mtd = nand_to_mtd(&denali->nand);
-	/*
-	 * Pre-compute DMA buffer size to avoid any problems in case
-	 * nand_release() ever changes in a way that mtd->writesize and
-	 * mtd->oobsize are not reliable after this call.
-	 */
-	int bufsize = mtd->writesize + mtd->oobsize;
 
 	nand_release(mtd);
 	denali_disable_irq(denali);
-	dma_unmap_single(denali->dev, denali->dma_addr, bufsize,
-			 DMA_BIDIRECTIONAL);
 }
 EXPORT_SYMBOL(denali_remove);
-- 
2.7.4

[PATCH v5 22/23] mtd: nand: denali: use non-managed kmalloc() for DMA buffer

[Masahiro Yamada]

As Russell and Lars stated in the discussion [1], using
devm_k*alloc() with DMA is not a good idea.

Let's use kmalloc (not kzalloc because no need for zero-out).
Also, allocate the buffer as late as possible because it must be
freed for any error that follows.

[1] https://lkml.org/lkml/2017/3/8/693

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 963638693850..904f859e19b6 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -23,6 +23,7 @@
 #include <linux/mutex.h>
 #include <linux/mtd/mtd.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 
 #include "denali.h"
 
@@ -1386,13 +1387,6 @@ int denali_init(struct denali_nand_info *denali)
 	if (ret)
 		goto disable_irq;
 
-	denali->buf = devm_kzalloc(denali->dev, mtd->writesize + mtd->oobsize,
-				   GFP_KERNEL);
-	if (!denali->buf) {
-		ret = -ENOMEM;
-		goto disable_irq;
-	}
-
 	if (ioread32(denali->flash_reg + FEATURES) & FEATURES__DMA)
 		denali->dma_avail = 1;
 
@@ -1477,17 +1471,30 @@ int denali_init(struct denali_nand_info *denali)
 	if (ret)
 		goto disable_irq;
 
+	/*
+	 * This buffer is DMA-mapped by denali_{read,write}_page_raw.  Do not
+	 * use devm_kmalloc() because the memory allocated by devm_ does not
+	 * guarantee DMA-safe alignment.
+	 */
+	denali->buf = kmalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
+	if (!denali->buf) {
+		ret = -ENOMEM;
+		goto disable_irq;
+	}
+
 	ret = nand_scan_tail(mtd);
 	if (ret)
-		goto disable_irq;
+		goto free_buf;
 
 	ret = mtd_device_register(mtd, NULL, 0);
 	if (ret) {
 		dev_err(denali->dev, "Failed to register MTD: %d\n", ret);
-		goto disable_irq;
+		goto free_buf;
 	}
 	return 0;
 
+free_buf:
+	kfree(denali->buf);
 disable_irq:
 	denali_disable_irq(denali);
 
@@ -1501,6 +1508,7 @@ void denali_remove(struct denali_nand_info *denali)
 	struct mtd_info *mtd = nand_to_mtd(&denali->nand);
 
 	nand_release(mtd);
+	kfree(denali->buf);
 	denali_disable_irq(denali);
 }
 EXPORT_SYMBOL(denali_remove);
-- 
2.7.4

[PATCH v5 23/23] mtd: nand: denali: enable bad block table scan

[Masahiro Yamada]

Now this driver is ready to remove NAND_SKIP_BBTSCAN.

The BBT descriptors in denali.c are equivalent to the ones in
nand_bbt.c.  There is no need to duplicate the equivalent structures.
The with-oob decriptors do not work for this driver anyway.

The bbt_pattern (offs = 8) and the version (veroffs = 12) area
overlaps the ECC area.  Set NAND_BBT_NO_OOB flag to use the no_oob
variant of the BBT descriptors.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
  - Newly added

 drivers/mtd/nand/denali.c | 31 ++-----------------------------
 1 file changed, 2 insertions(+), 29 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 904f859e19b6..43006c506a6b 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -1247,29 +1247,6 @@ static const struct mtd_ooblayout_ops denali_ooblayout_ops = {
 	.free = denali_ooblayout_free,
 };
 
-static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
-static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
-
-static struct nand_bbt_descr bbt_main_descr = {
-	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
-	.offs =	8,
-	.len = 4,
-	.veroffs = 12,
-	.maxblocks = 4,
-	.pattern = bbt_pattern,
-};
-
-static struct nand_bbt_descr bbt_mirror_descr = {
-	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
-	.offs =	8,
-	.len = 4,
-	.veroffs = 12,
-	.maxblocks = 4,
-	.pattern = mirror_pattern,
-};
-
 /* initialize driver data structures */
 static void denali_drv_init(struct denali_nand_info *denali)
 {
@@ -1412,13 +1389,9 @@ int denali_init(struct denali_nand_info *denali)
 	 * bad block management.
 	 */
 
-	/* Bad block management */
-	chip->bbt_td = &bbt_main_descr;
-	chip->bbt_md = &bbt_mirror_descr;
-
-	/* skip the scan for now until we have OOB read and write support */
 	chip->bbt_options |= NAND_BBT_USE_FLASH;
-	chip->options |= NAND_SKIP_BBTSCAN;
+	chip->bbt_options |= NAND_BBT_NO_OOB;
+
 	chip->ecc.mode = NAND_ECC_HW_SYNDROME;
 
 	/* no subpage writes on denali */
-- 
2.7.4

Re: [PATCH v5 06/23] mtd: nand: denali: set NAND_ECC_CUSTOM_PAGE_ACCESS

[Boris Brezillon]

On Wed,  7 Jun 2017 20:52:15 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> The denali_cmdfunc() actually does nothing valuable for
> NAND_CMD_{PAGEPROG,READ0,SEQIN}.
> 
> For NAND_CMD_{READ0,SEQIN}, it copies "page" to "denali->page", then
> denali_read_page() and denali_read_page_raw() compare them to check
> if the NAND framework called the callbacks in correct order.
> (Inconsistently, this check is missing from the denali_write_page()
> and denali_write_page_raw().)
> 
> The framework is widely tested by many drivers, so this kind of
> sanity check is unneeded.  The Denali controller is equipped with
> high level interface for read/write, so let's skip unneeded call
> of cmdfunc().

I recently changed the semantic of ecc->write_page[_raw]() when
NAND_ECC_CUSTOM_PAGE_ACCESS is set [1]. I'm not sure your driver waits
for the program command to finish.
I think you should wait for INTR_STATUS__PROGRAM_COMP instead of
INTR_STATUS__DMA_CMD_COMP in write_page() [2], as is done in
write_oob_data().

Note that, even though you listen to INTR_STATUS__PROGRAM_FAIL, you
never test the value of irq_status when it != 0, which means you don't
detect PROG failures.

[1]http://git.infradead.org/l2-mtd.git/commit/41145649f4acb30249b636b945053db50c9331c5
[2]http://elixir.free-electrons.com/linux/latest/source/drivers/mtd/nand/denali.c#L1029

> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2:
>   - Newly added
> 
>  drivers/mtd/nand/denali.c | 29 ++++++++---------------------
>  1 file changed, 8 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> index 991924b9ae2c..1897fe238290 100644
> --- a/drivers/mtd/nand/denali.c
> +++ b/drivers/mtd/nand/denali.c
> @@ -998,7 +998,7 @@ static void denali_setup_dma(struct denali_nand_info *denali, int op)
>   * configuration details.
>   */
>  static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
> -			const uint8_t *buf, bool raw_xfer)
> +			const uint8_t *buf, int page, bool raw_xfer)
>  {
>  	struct denali_nand_info *denali = mtd_to_denali(mtd);
>  	dma_addr_t addr = denali->buf.dma_buf;
> @@ -1006,6 +1006,8 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>  	uint32_t irq_status;
>  	uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
>  
> +	denali->page = page;
> +
>  	/*
>  	 * if it is a raw xfer, we want to disable ecc and send the spare area.
>  	 * !raw_xfer - enable ecc
> @@ -1059,7 +1061,7 @@ static int denali_write_page(struct mtd_info *mtd, struct nand_chip *chip,
>  	 * for regular page writes, we let HW handle all the ECC
>  	 * data written to the device.
>  	 */
> -	return write_page(mtd, chip, buf, false);
> +	return write_page(mtd, chip, buf, page, false);
>  }
>  
>  /*
> @@ -1075,7 +1077,7 @@ static int denali_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
>  	 * for raw page writes, we want to disable ECC and simply write
>  	 * whatever data is in the buffer.
>  	 */
> -	return write_page(mtd, chip, buf, true);
> +	return write_page(mtd, chip, buf, page, true);
>  }
>  
>  static int denali_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
> @@ -1105,12 +1107,7 @@ static int denali_read_page(struct mtd_info *mtd, struct nand_chip *chip,
>  	unsigned long uncor_ecc_flags = 0;
>  	int stat = 0;
>  
> -	if (page != denali->page) {
> -		dev_err(denali->dev,
> -			"IN %s: page %d is not equal to denali->page %d",
> -			__func__, page, denali->page);
> -		BUG();
> -	}
> +	denali->page = page;
>  
>  	setup_ecc_for_xfer(denali, true, false);
>  
> @@ -1154,12 +1151,7 @@ static int denali_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
>  	size_t size = mtd->writesize + mtd->oobsize;
>  	uint32_t irq_mask = INTR__DMA_CMD_COMP;
>  
> -	if (page != denali->page) {
> -		dev_err(denali->dev,
> -			"IN %s: page %d is not equal to denali->page %d",
> -			__func__, page, denali->page);
> -		BUG();
> -	}
> +	denali->page = page;
>  
>  	setup_ecc_for_xfer(denali, false, true);
>  	denali_enable_dma(denali, true);
> @@ -1238,8 +1230,6 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
>  	int i;
>  
>  	switch (cmd) {
> -	case NAND_CMD_PAGEPROG:
> -		break;
>  	case NAND_CMD_STATUS:
>  		read_status(denali);
>  		break;
> @@ -1259,10 +1249,6 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
>  			write_byte_to_buf(denali, id);
>  		}
>  		break;
> -	case NAND_CMD_READ0:
> -	case NAND_CMD_SEQIN:
> -		denali->page = page;
> -		break;
>  	case NAND_CMD_RESET:
>  		reset_bank(denali);
>  		break;
> @@ -1603,6 +1589,7 @@ int denali_init(struct denali_nand_info *denali)
>  
>  	mtd_set_ooblayout(mtd, &denali_ooblayout_ops);
>  
> +	chip->ecc.options |= NAND_ECC_CUSTOM_PAGE_ACCESS;
>  	chip->ecc.read_page = denali_read_page;
>  	chip->ecc.read_page_raw = denali_read_page_raw;
>  	chip->ecc.write_page = denali_write_page;

Re: [PATCH v5 07/23] mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()

[Boris Brezillon]

On Wed,  7 Jun 2017 20:52:16 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Currently, the error handling of denali_write_page(_raw) is a bit
> complicated.  If the program command fails, NAND_STATUS_FAIL is set
> to the driver internal denali->status, then read out later by
> denali_waitfunc().
> 
> We can avoid it by exploiting the nand_write_page() implementation.
> If chip->ecc.write_page(_raw) returns negative code (i.e. -EIO), it
> errors out immediately.  This gives the same result as returning
> NAND_STATUS_FAIL from chip->waitfunc.  In either way, -EIO is
> returned to the upper MTD layer.

Actually, this is how it's supposed to work now (when they set
the NAND_ECC_CUSTOM_PAGE_ACCESS flag, drivers are expected to wait for
the program operation to finish and return -EIO if it failed), so you're
all good ;-).

> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2:
>   - Newly added
> 
>  drivers/mtd/nand/denali.c | 12 ++++--------
>  drivers/mtd/nand/denali.h |  1 -
>  2 files changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> index 1897fe238290..22acfc34b546 100644
> --- a/drivers/mtd/nand/denali.c
> +++ b/drivers/mtd/nand/denali.c
> @@ -1005,6 +1005,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>  	size_t size = mtd->writesize + mtd->oobsize;
>  	uint32_t irq_status;
>  	uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;

As mentioned in my previous patch, I think you should wait for
INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL here.

> +	int ret = 0;
>  
>  	denali->page = page;
>  
> @@ -1038,13 +1039,13 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>  	if (irq_status == 0) {
>  		dev_err(denali->dev, "timeout on write_page (type = %d)\n",
>  			raw_xfer);
> -		denali->status = NAND_STATUS_FAIL;
> +		ret = -EIO;
>  	}

	if (irq_status & INTR__PROGRAM_FAIL) {
		dev_err(denali->dev, "page program failed (type = %d)\n",
  			raw_xfer);
		ret = -EIO;
	}
>  
>  	denali_enable_dma(denali, false);
>  	dma_sync_single_for_cpu(denali->dev, addr, size, DMA_TO_DEVICE);
>  
> -	return 0;
> +	return ret;
>  }
>  
>  /* NAND core entry points */
> @@ -1196,12 +1197,7 @@ static void denali_select_chip(struct mtd_info *mtd, int chip)
>  
>  static int denali_waitfunc(struct mtd_info *mtd, struct nand_chip *chip)
>  {
> -	struct denali_nand_info *denali = mtd_to_denali(mtd);
> -	int status = denali->status;
> -
> -	denali->status = 0;
> -
> -	return status;
> +	return 0;
>  }
>  
>  static int denali_erase(struct mtd_info *mtd, int page)
> diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
> index a06ed741b550..352d8328b94a 100644
> --- a/drivers/mtd/nand/denali.h
> +++ b/drivers/mtd/nand/denali.h
> @@ -323,7 +323,6 @@ struct nand_buf {
>  struct denali_nand_info {
>  	struct nand_chip nand;
>  	int flash_bank; /* currently selected chip */
> -	int status;
>  	int platform;
>  	struct nand_buf buf;
>  	struct device *dev;

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Boris Brezillon]

On Wed,  7 Jun 2017 20:52:19 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:


> -/*
> - * This is the interrupt service routine. It handles all interrupts
> - * sent to this device. Note that on CE4100, this is a shared interrupt.
> - */
> -static irqreturn_t denali_isr(int irq, void *dev_id)
> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
> +				    uint32_t irq_mask)
>  {
> -	struct denali_nand_info *denali = dev_id;
> +	unsigned long time_left, flags;
>  	uint32_t irq_status;
> -	irqreturn_t result = IRQ_NONE;
>  
> -	spin_lock(&denali->irq_lock);
> +	spin_lock_irqsave(&denali->irq_lock, flags);
>  
> -	/* check to see if a valid NAND chip has been selected. */
> -	if (is_flash_bank_valid(denali->flash_bank)) {
> -		/*
> -		 * check to see if controller generated the interrupt,
> -		 * since this is a shared interrupt
> -		 */
> -		irq_status = denali_irq_detected(denali);
> -		if (irq_status != 0) {
> -			/* handle interrupt */
> -			/* first acknowledge it */
> -			clear_interrupt(denali, irq_status);
> -			/*
> -			 * store the status in the device context for someone
> -			 * to read
> -			 */
> -			denali->irq_status |= irq_status;
> -			/* notify anyone who cares that it happened */
> -			complete(&denali->complete);
> -			/* tell the OS that we've handled this */
> -			result = IRQ_HANDLED;
> -		}
> +	irq_status = denali->irq_status;
> +
> +	if (irq_mask & irq_status) {
> +		spin_unlock_irqrestore(&denali->irq_lock, flags);
> +		return irq_status;
>  	}
> -	spin_unlock(&denali->irq_lock);
> -	return result;
> +
> +	denali->irq_mask = irq_mask;
> +	reinit_completion(&denali->complete);

These 2 instructions should be done before calling
denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
you might loose events if they happen between your irq_status read and
the reinit_completion() call. You should also clear existing interrupts
before launching your operation, otherwise you might wakeup on previous
events.

> +	spin_unlock_irqrestore(&denali->irq_lock, flags);
> +
> +	time_left = wait_for_completion_timeout(&denali->complete,
> +						msecs_to_jiffies(1000));
> +	if (!time_left) {
> +		dev_err(denali->dev, "timeout while waiting for irq 0x%x\n",
> +			denali->irq_mask);
> +		return 0;
> +	}
> +
> +	return denali->irq_status;
>  }
>  

Re: [PATCH v5 19/23] mtd: nand: denali: fix raw and oob accessors for syndrome page layout

[Boris Brezillon]

On Wed,  7 Jun 2017 20:52:28 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

>  
> +static void denali_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
> +{
> +	struct denali_nand_info *denali = mtd_to_denali(mtd);
> +	int i;
> +
> +	iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);

What is this '| 2'? You seem to use it a lot. Can you define a macro
and maybe add a comment if the macro name is not self-descriptive.

Re: [PATCH v5 05/23] mtd: nand: denali_dt: add compatible strings for UniPhier SoC variants

[Rob Herring]

On Wed, Jun 07, 2017 at 08:52:14PM +0900, Masahiro Yamada wrote:
> Add two compatible strings for UniPhier SoC family.
> 
> "socionext,uniphier-denali-nand-v5a" is used on UniPhier sLD3, LD4,
> Pro4, sLD8.
> 
> "socionext,uniphier-denali-nand-v5b" is used on UniPhier Pro5, PXs2,
> LD6b, LD11, LD20.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
> Changes in v5:
>   - Adjust to the update of generic helpers
> 
> Changes in v4:
>   - Adjusted to generic helpers for ECC engine caps
> 
> Changes in v3: None
> Changes in v2:
>   - Change the compatible strings
>   - Fix the ecc_strength_capability
>   - Override revision number for the newer one
> 
>  .../devicetree/bindings/mtd/denali-nand.txt        |  6 ++++++

I acked v3. Please add acks when posting new versions.

Rob

>  drivers/mtd/nand/denali_dt.c                       | 25 ++++++++++++++++++++++
>  2 files changed, 31 insertions(+)

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Masahiro Yamada]

Hi Boris,


2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Wed,  7 Jun 2017 20:52:19 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>
>> -/*
>> - * This is the interrupt service routine. It handles all interrupts
>> - * sent to this device. Note that on CE4100, this is a shared interrupt.
>> - */
>> -static irqreturn_t denali_isr(int irq, void *dev_id)
>> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
>> +                                 uint32_t irq_mask)
>>  {
>> -     struct denali_nand_info *denali = dev_id;
>> +     unsigned long time_left, flags;
>>       uint32_t irq_status;
>> -     irqreturn_t result = IRQ_NONE;
>>
>> -     spin_lock(&denali->irq_lock);
>> +     spin_lock_irqsave(&denali->irq_lock, flags);
>>
>> -     /* check to see if a valid NAND chip has been selected. */
>> -     if (is_flash_bank_valid(denali->flash_bank)) {
>> -             /*
>> -              * check to see if controller generated the interrupt,
>> -              * since this is a shared interrupt
>> -              */
>> -             irq_status = denali_irq_detected(denali);
>> -             if (irq_status != 0) {
>> -                     /* handle interrupt */
>> -                     /* first acknowledge it */
>> -                     clear_interrupt(denali, irq_status);
>> -                     /*
>> -                      * store the status in the device context for someone
>> -                      * to read
>> -                      */
>> -                     denali->irq_status |= irq_status;
>> -                     /* notify anyone who cares that it happened */
>> -                     complete(&denali->complete);
>> -                     /* tell the OS that we've handled this */
>> -                     result = IRQ_HANDLED;
>> -             }
>> +     irq_status = denali->irq_status;
>> +
>> +     if (irq_mask & irq_status) {
>> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
>> +             return irq_status;
>>       }
>> -     spin_unlock(&denali->irq_lock);
>> -     return result;
>> +
>> +     denali->irq_mask = irq_mask;
>> +     reinit_completion(&denali->complete);
>
> These 2 instructions should be done before calling
> denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
> you might loose events if they happen between your irq_status read and
> the reinit_completion() call.

No.

denali->irq_lock avoids a race between denali_isr() and
denali_wait_for_irq().


The line
     denali->irq_status |= irq_status;
in denali_isr() accumulates all events that have happened
since denali_reset_irq().

If the interested IRQs have already happened
before denali_wait_for_irq(), it just return immediately
without using completion.

I do not mind adding a comment like below
if you think my intention is unclear, though.

        /* Return immediately if interested IRQs have already happend. */
        if (irq_mask & irq_status) {
                spin_unlock_irqrestore(&denali->irq_lock, flags);
                return irq_status;
        }





> You should also clear existing interrupts
> before launching your operation, otherwise you might wakeup on previous
> events.


I do not see a point in your suggestion.

denali_isr() reads out IRQ_STATUS(i) and immediately clears IRQ bits.

IRQ events triggered by previous events are accumulated in denali->irq_status.

denali_reset_irq() clears it.

        denali->irq_status = 0;


Again, denali->irq_lock avoids a race between denali_reset_irq() and
denali_irq(),
so this works correctly.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 07/23] mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()

[Masahiro Yamada]

Hi Boris,


2017-06-07 22:33 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Wed,  7 Jun 2017 20:52:16 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> Currently, the error handling of denali_write_page(_raw) is a bit
>> complicated.  If the program command fails, NAND_STATUS_FAIL is set
>> to the driver internal denali->status, then read out later by
>> denali_waitfunc().
>>
>> We can avoid it by exploiting the nand_write_page() implementation.
>> If chip->ecc.write_page(_raw) returns negative code (i.e. -EIO), it
>> errors out immediately.  This gives the same result as returning
>> NAND_STATUS_FAIL from chip->waitfunc.  In either way, -EIO is
>> returned to the upper MTD layer.
>
> Actually, this is how it's supposed to work now (when they set
> the NAND_ECC_CUSTOM_PAGE_ACCESS flag, drivers are expected to wait for
> the program operation to finish and return -EIO if it failed), so you're
> all good ;-).
>
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> ---
>>
>> Changes in v5: None
>> Changes in v4: None
>> Changes in v3: None
>> Changes in v2:
>>   - Newly added
>>
>>  drivers/mtd/nand/denali.c | 12 ++++--------
>>  drivers/mtd/nand/denali.h |  1 -
>>  2 files changed, 4 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
>> index 1897fe238290..22acfc34b546 100644
>> --- a/drivers/mtd/nand/denali.c
>> +++ b/drivers/mtd/nand/denali.c
>> @@ -1005,6 +1005,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>>       size_t size = mtd->writesize + mtd->oobsize;
>>       uint32_t irq_status;
>>       uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
>
> As mentioned in my previous patch, I think you should wait for
> INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL here.

No.
It is intentional to use INTR__DMA_CMD_COMP
instead of INTR__PROGRAM_COMP here.


This is very strange of this IP,
INTR__PROGRAM_COMP is never set when DMA mode is being used.
(INTR__DMA_CMD_COMP is set instead.)


As far as I tested this IP,
INTR__PROGRAM_COMP is set only when data are written by PIO mode.


I introduced PIO transfer in
http://patchwork.ozlabs.org/patch/772398/

I used INTR__PROGRAM_COMP in denali_pio_write().



>> +     int ret = 0;
>>
>>       denali->page = page;
>>
>> @@ -1038,13 +1039,13 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>>       if (irq_status == 0) {
>>               dev_err(denali->dev, "timeout on write_page (type = %d)\n",
>>                       raw_xfer);
>> -             denali->status = NAND_STATUS_FAIL;
>> +             ret = -EIO;
>>       }
>
>         if (irq_status & INTR__PROGRAM_FAIL) {
>                 dev_err(denali->dev, "page program failed (type = %d)\n",
>                         raw_xfer);
>                 ret = -EIO;
>         }

This will be fixed anyway by
http://patchwork.ozlabs.org/patch/772414/


I do not want to include unrelated change.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 00/23] mtd: nand: denali: Denali NAND IP patch bomb

[Masahiro Yamada]

Hi Boris,

2017-06-07 20:52 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> This patch series intends to solve various problems.
>
> [1] The driver just retrieves the OOB area as-is
>     whereas the controller uses syndrome page layout.
> [2] Many NAND chip specific parameters are hard-coded in the driver.
> [3] ONFi devices are not working
> [4] It can not read Bad Block Marker
>
> Outstanding changes are:
> - Fix raw/oob callbacks for syndrome page layout
> - Implement setup_data_interface() callback
> - Fix/implement more commands for ONFi devices
> - Allow to skip the driver internal bounce buffer
> - Support PIO in case DMA is not supported
> - Switch from ->cmdfunc over to ->cmd_ctrl


I am planning v6, but
how many can you pick-up from this series?

I did not see your comments for 01-05, so are they applicable?

Could you add
Acked-by: Rob Herring <robh@kernel.org>
for 05  (http://patchwork.ozlabs.org/patch/772388/)

He had already acked it, but I just missed it.



-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 07/23] mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()

[Boris Brezillon]

Le Thu, 8 Jun 2017 15:11:03 +0900,
Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :

> Hi Boris,
> 
> 
> 2017-06-07 22:33 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> > On Wed,  7 Jun 2017 20:52:16 +0900
> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >  
> >> Currently, the error handling of denali_write_page(_raw) is a bit
> >> complicated.  If the program command fails, NAND_STATUS_FAIL is set
> >> to the driver internal denali->status, then read out later by
> >> denali_waitfunc().
> >>
> >> We can avoid it by exploiting the nand_write_page() implementation.
> >> If chip->ecc.write_page(_raw) returns negative code (i.e. -EIO), it
> >> errors out immediately.  This gives the same result as returning
> >> NAND_STATUS_FAIL from chip->waitfunc.  In either way, -EIO is
> >> returned to the upper MTD layer.  
> >
> > Actually, this is how it's supposed to work now (when they set
> > the NAND_ECC_CUSTOM_PAGE_ACCESS flag, drivers are expected to wait for
> > the program operation to finish and return -EIO if it failed), so you're
> > all good ;-).
> >  
> >>
> >> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> >> ---
> >>
> >> Changes in v5: None
> >> Changes in v4: None
> >> Changes in v3: None
> >> Changes in v2:
> >>   - Newly added
> >>
> >>  drivers/mtd/nand/denali.c | 12 ++++--------
> >>  drivers/mtd/nand/denali.h |  1 -
> >>  2 files changed, 4 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> >> index 1897fe238290..22acfc34b546 100644
> >> --- a/drivers/mtd/nand/denali.c
> >> +++ b/drivers/mtd/nand/denali.c
> >> @@ -1005,6 +1005,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
> >>       size_t size = mtd->writesize + mtd->oobsize;
> >>       uint32_t irq_status;
> >>       uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;  
> >
> > As mentioned in my previous patch, I think you should wait for
> > INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL here.  
> 
> No.
> It is intentional to use INTR__DMA_CMD_COMP
> instead of INTR__PROGRAM_COMP here.
> 
> 
> This is very strange of this IP,
> INTR__PROGRAM_COMP is never set when DMA mode is being used.
> (INTR__DMA_CMD_COMP is set instead.)

Indeed, this is really strange. Are you sure the page is actually
programmed when you receive the INTR__DMA_CMD_COMP interrupt?
Because INTR__DMA_CMD_COMP is likely to happen before the PAGEPROG
command has finished, which is not good (the core might start a new
operation while the NAND is still busy).

Anyway, if INTR__DMA_CMD_COMP is what should be set, it clearly
deserves a comment.

> 
> 
> As far as I tested this IP,
> INTR__PROGRAM_COMP is set only when data are written by PIO mode.

It doesn't make much sense (not saying you're wrong, just that the IP
is weird). PROG completed should be independent of the data transfer
step. Sure it happens after transferring data to the NAND, but then you
still have to execute the PAGEPROG command and wait until the NAND
becomes ready again. That's when I'd expect PROGRAM_COMP (or
PROGRAM_FAIL) to be triggered.

> 
> 
> I introduced PIO transfer in
> http://patchwork.ozlabs.org/patch/772398/
> 
> I used INTR__PROGRAM_COMP in denali_pio_write().
> 

Yep, I see that.

> 
> 
> >> +     int ret = 0;
> >>
> >>       denali->page = page;
> >>
> >> @@ -1038,13 +1039,13 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
> >>       if (irq_status == 0) {
> >>               dev_err(denali->dev, "timeout on write_page (type = %d)\n",
> >>                       raw_xfer);
> >> -             denali->status = NAND_STATUS_FAIL;
> >> +             ret = -EIO;
> >>       }  
> >
> >         if (irq_status & INTR__PROGRAM_FAIL) {
> >                 dev_err(denali->dev, "page program failed (type = %d)\n",
> >                         raw_xfer);
> >                 ret = -EIO;
> >         }  
> 
> This will be fixed anyway by
> http://patchwork.ozlabs.org/patch/772414/

Note that PROG_FAILED is quite different from a timeout (usually
happens when a block becomes bad), so it probably deserve a specific
error message.

> 
> 
> I do not want to include unrelated change.
> 
> 

Okay.

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Boris Brezillon]

Le Thu, 8 Jun 2017 15:10:18 +0900,
Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :

> Hi Boris,
> 
> 
> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> > On Wed,  7 Jun 2017 20:52:19 +0900
> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >
> >  
> >> -/*
> >> - * This is the interrupt service routine. It handles all interrupts
> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
> >> - */
> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
> >> +                                 uint32_t irq_mask)
> >>  {
> >> -     struct denali_nand_info *denali = dev_id;
> >> +     unsigned long time_left, flags;
> >>       uint32_t irq_status;
> >> -     irqreturn_t result = IRQ_NONE;
> >>
> >> -     spin_lock(&denali->irq_lock);
> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
> >>
> >> -     /* check to see if a valid NAND chip has been selected. */
> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
> >> -             /*
> >> -              * check to see if controller generated the interrupt,
> >> -              * since this is a shared interrupt
> >> -              */
> >> -             irq_status = denali_irq_detected(denali);
> >> -             if (irq_status != 0) {
> >> -                     /* handle interrupt */
> >> -                     /* first acknowledge it */
> >> -                     clear_interrupt(denali, irq_status);
> >> -                     /*
> >> -                      * store the status in the device context for someone
> >> -                      * to read
> >> -                      */
> >> -                     denali->irq_status |= irq_status;
> >> -                     /* notify anyone who cares that it happened */
> >> -                     complete(&denali->complete);
> >> -                     /* tell the OS that we've handled this */
> >> -                     result = IRQ_HANDLED;
> >> -             }
> >> +     irq_status = denali->irq_status;
> >> +
> >> +     if (irq_mask & irq_status) {
> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
> >> +             return irq_status;
> >>       }
> >> -     spin_unlock(&denali->irq_lock);
> >> -     return result;
> >> +
> >> +     denali->irq_mask = irq_mask;
> >> +     reinit_completion(&denali->complete);  
> >
> > These 2 instructions should be done before calling
> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
> > you might loose events if they happen between your irq_status read and
> > the reinit_completion() call.  
> 
> No.
> 
> denali->irq_lock avoids a race between denali_isr() and
> denali_wait_for_irq().
> 
> 
> The line
>      denali->irq_status |= irq_status;
> in denali_isr() accumulates all events that have happened
> since denali_reset_irq().
> 
> If the interested IRQs have already happened
> before denali_wait_for_irq(), it just return immediately
> without using completion.
> 
> I do not mind adding a comment like below
> if you think my intention is unclear, though.
> 
>         /* Return immediately if interested IRQs have already happend. */
>         if (irq_mask & irq_status) {
>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
>                 return irq_status;
>         }
> 
> 

My bad, I didn't notice you were releasing the lock after calling
reinit_completion(). I still find this solution more complex than my
proposal, but I don't care that much.

> 
> 
> 
> > You should also clear existing interrupts
> > before launching your operation, otherwise you might wakeup on previous
> > events.  
> 
> 
> I do not see a point in your suggestion.
> 
> denali_isr() reads out IRQ_STATUS(i) and immediately clears IRQ bits.
> 
> IRQ events triggered by previous events are accumulated in denali->irq_status.
> 
> denali_reset_irq() clears it.
> 
>         denali->irq_status = 0;

Well, it was just a precaution, in case some interrupts weren't cleared
during the previous test (for example if they were masked before the
event actually happened, which can occur if you have a timeout, but
the event is detected afterward).

> 
> 
> Again, denali->irq_lock avoids a race between denali_reset_irq() and
> denali_irq(),
> so this works correctly.
> 
> 

Anyway, you seem confident that you're doing the right thing, so I'll
let you decide what is appropriate and redirect any bug report to you if
that happens :-P.

Re: [PATCH v5 00/23] mtd: nand: denali: Denali NAND IP patch bomb

[Masahiro Yamada]

2017-06-08 15:16 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> Hi Boris,
>
> 2017-06-07 20:52 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
>> This patch series intends to solve various problems.
>>
>> [1] The driver just retrieves the OOB area as-is
>>     whereas the controller uses syndrome page layout.
>> [2] Many NAND chip specific parameters are hard-coded in the driver.
>> [3] ONFi devices are not working
>> [4] It can not read Bad Block Marker
>>
>> Outstanding changes are:
>> - Fix raw/oob callbacks for syndrome page layout
>> - Implement setup_data_interface() callback
>> - Fix/implement more commands for ONFi devices
>> - Allow to skip the driver internal bounce buffer
>> - Support PIO in case DMA is not supported
>> - Switch from ->cmdfunc over to ->cmd_ctrl
>
>
> I am planning v6, but
> how many can you pick-up from this series?
>
> I did not see your comments for 01-05, so are they applicable?
>
> Could you add
> Acked-by: Rob Herring <robh@kernel.org>
> for 05  (http://patchwork.ozlabs.org/patch/772388/)
>
> He had already acked it, but I just missed it.
>

BTW, this series can not apply to Boris's tree
because of the following commit.

commit 4a78cc644eed3cf2dae00c3a959910a86c140fd6
Author: Boris Brezillon <boris.brezillon@free-electrons.com>
Date:   Fri May 26 17:10:15 2017 +0200

    mtd: nand: Make sure drivers not supporting SET/GET_FEATURES
return -ENOTSUPP



I will send v6 rebased on nand/next branch.



-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 00/23] mtd: nand: denali: Denali NAND IP patch bomb

[Boris Brezillon]

Le Thu, 8 Jun 2017 15:16:53 +0900,
Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :

> Hi Boris,
> 
> 2017-06-07 20:52 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> > This patch series intends to solve various problems.
> >
> > [1] The driver just retrieves the OOB area as-is
> >     whereas the controller uses syndrome page layout.
> > [2] Many NAND chip specific parameters are hard-coded in the driver.
> > [3] ONFi devices are not working
> > [4] It can not read Bad Block Marker
> >
> > Outstanding changes are:
> > - Fix raw/oob callbacks for syndrome page layout
> > - Implement setup_data_interface() callback
> > - Fix/implement more commands for ONFi devices
> > - Allow to skip the driver internal bounce buffer
> > - Support PIO in case DMA is not supported
> > - Switch from ->cmdfunc over to ->cmd_ctrl  
> 
> 
> I am planning v6, but
> how many can you pick-up from this series?
> 
> I did not see your comments for 01-05, so are they applicable?

They look good. Didn't apply them yet though.

> 
> Could you add
> Acked-by: Rob Herring <robh@kernel.org>
> for 05  (http://patchwork.ozlabs.org/patch/772388/)
> 
> He had already acked it, but I just missed it.

Yep, will do.

Re: [PATCH v5 00/23] mtd: nand: denali: Denali NAND IP patch bomb

[Boris Brezillon]

Le Thu, 8 Jun 2017 16:12:49 +0900,
Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :

> 2017-06-08 15:16 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> > Hi Boris,
> >
> > 2017-06-07 20:52 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:  
> >> This patch series intends to solve various problems.
> >>
> >> [1] The driver just retrieves the OOB area as-is
> >>     whereas the controller uses syndrome page layout.
> >> [2] Many NAND chip specific parameters are hard-coded in the driver.
> >> [3] ONFi devices are not working
> >> [4] It can not read Bad Block Marker
> >>
> >> Outstanding changes are:
> >> - Fix raw/oob callbacks for syndrome page layout
> >> - Implement setup_data_interface() callback
> >> - Fix/implement more commands for ONFi devices
> >> - Allow to skip the driver internal bounce buffer
> >> - Support PIO in case DMA is not supported
> >> - Switch from ->cmdfunc over to ->cmd_ctrl  
> >
> >
> > I am planning v6, but
> > how many can you pick-up from this series?
> >
> > I did not see your comments for 01-05, so are they applicable?
> >
> > Could you add
> > Acked-by: Rob Herring <robh@kernel.org>
> > for 05  (http://patchwork.ozlabs.org/patch/772388/)
> >
> > He had already acked it, but I just missed it.
> >  
> 
> BTW, this series can not apply to Boris's tree
> because of the following commit.
> 
> commit 4a78cc644eed3cf2dae00c3a959910a86c140fd6
> Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> Date:   Fri May 26 17:10:15 2017 +0200
> 
>     mtd: nand: Make sure drivers not supporting SET/GET_FEATURES
> return -ENOTSUPP
> 
> 
> 
> I will send v6 rebased on nand/next branch.
> 

Please wait a bit before spamming the ML again. I'd like to finish
reviewing patches and apply uncontroversial ones.

Re: [PATCH v5 06/23] mtd: nand: denali: set NAND_ECC_CUSTOM_PAGE_ACCESS

[Masahiro Yamada]

Hi Boris

2017-06-07 22:26 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Wed,  7 Jun 2017 20:52:15 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> The denali_cmdfunc() actually does nothing valuable for
>> NAND_CMD_{PAGEPROG,READ0,SEQIN}.
>>
>> For NAND_CMD_{READ0,SEQIN}, it copies "page" to "denali->page", then
>> denali_read_page() and denali_read_page_raw() compare them to check
>> if the NAND framework called the callbacks in correct order.
>> (Inconsistently, this check is missing from the denali_write_page()
>> and denali_write_page_raw().)
>>
>> The framework is widely tested by many drivers, so this kind of
>> sanity check is unneeded.  The Denali controller is equipped with
>> high level interface for read/write, so let's skip unneeded call
>> of cmdfunc().
>
> I recently changed the semantic of ecc->write_page[_raw]() when
> NAND_ECC_CUSTOM_PAGE_ACCESS is set [1]. I'm not sure your driver waits
> for the program command to finish.
> I think you should wait for INTR_STATUS__PROGRAM_COMP instead of
> INTR_STATUS__DMA_CMD_COMP in write_page() [2], as is done in
> write_oob_data().

Thanks for the pointer.

I missed your commit because I usually develop based on
Linus' tree instead of linux-next.

I will fix this commit.



-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 07/23] mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()

[Masahiro Yamada]

Hi Boris,


2017-06-08 16:05 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> Le Thu, 8 Jun 2017 15:11:03 +0900,
> Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
>
>> Hi Boris,
>>
>>
>> 2017-06-07 22:33 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> > On Wed,  7 Jun 2017 20:52:16 +0900
>> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >
>> >> Currently, the error handling of denali_write_page(_raw) is a bit
>> >> complicated.  If the program command fails, NAND_STATUS_FAIL is set
>> >> to the driver internal denali->status, then read out later by
>> >> denali_waitfunc().
>> >>
>> >> We can avoid it by exploiting the nand_write_page() implementation.
>> >> If chip->ecc.write_page(_raw) returns negative code (i.e. -EIO), it
>> >> errors out immediately.  This gives the same result as returning
>> >> NAND_STATUS_FAIL from chip->waitfunc.  In either way, -EIO is
>> >> returned to the upper MTD layer.
>> >
>> > Actually, this is how it's supposed to work now (when they set
>> > the NAND_ECC_CUSTOM_PAGE_ACCESS flag, drivers are expected to wait for
>> > the program operation to finish and return -EIO if it failed), so you're
>> > all good ;-).
>> >
>> >>
>> >> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> >> ---
>> >>
>> >> Changes in v5: None
>> >> Changes in v4: None
>> >> Changes in v3: None
>> >> Changes in v2:
>> >>   - Newly added
>> >>
>> >>  drivers/mtd/nand/denali.c | 12 ++++--------
>> >>  drivers/mtd/nand/denali.h |  1 -
>> >>  2 files changed, 4 insertions(+), 9 deletions(-)
>> >>
>> >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
>> >> index 1897fe238290..22acfc34b546 100644
>> >> --- a/drivers/mtd/nand/denali.c
>> >> +++ b/drivers/mtd/nand/denali.c
>> >> @@ -1005,6 +1005,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>> >>       size_t size = mtd->writesize + mtd->oobsize;
>> >>       uint32_t irq_status;
>> >>       uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
>> >
>> > As mentioned in my previous patch, I think you should wait for
>> > INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL here.
>>
>> No.
>> It is intentional to use INTR__DMA_CMD_COMP
>> instead of INTR__PROGRAM_COMP here.
>>
>>
>> This is very strange of this IP,
>> INTR__PROGRAM_COMP is never set when DMA mode is being used.
>> (INTR__DMA_CMD_COMP is set instead.)
>
> Indeed, this is really strange. Are you sure the page is actually
> programmed when you receive the INTR__DMA_CMD_COMP interrupt?

Yes.
After my test, I concluded INTR__DMA_CMD_COMP is asserted
when page program is completed.



Rationale:

Denali User's Guide describes the IRQ bits as follows:


Bit 2 (dma_cmd_comp)    A data DMA command has completed on this bank
  ...
Bit 7 (program_comp)    Device finished the last issued program command
  ...
Bit 12 (INT_act)        R/B pin of device transitioned from low to high
  ...
Bit 15 (page_xfer_inc)  For every page of data transfer to or from the device,
                        this bit will be set.



In my test,  ->write_page() hook triggers IRQ bits as follows:

 - Write access with DMA
      bit 15 is asserted first,
      then some timer later  bit 12 and bit 2 are asserted at the same time

 - Write access with PIO
      bit 15 is asserted first,
      then some time later   bit 12 and bit 7 are asserted at the same time



NAND devices toggle R/B# pin when page program is completed.
So, bit 2 (dma_cmd_comp) means the completion of page program.


I assume your next question here.
"So, why don't you wait for INTR__INT_ACT
instead of INTR__DMA_CMD_COMP / INTR__PROGRAM_COMP?
It should work regardless of transfer mode."
This has a point.
We can always check R/B# transition for read, write, erase, or whatever.
This is just a matter of taste, but I am just keeping code that uses
dedicated IRQ bits for each mode.





> Because INTR__DMA_CMD_COMP is likely to happen before the PAGEPROG
> command has finished, which is not good (the core might start a new
> operation while the NAND is still busy).

As explained above, INTR__PAGE_XFER_INC happens before the PAGEPROG.
Then, INTR__DMA_CMD_COMP happens when the PAGEPROG has finished.



> Anyway, if INTR__DMA_CMD_COMP is what should be set, it clearly
> deserves a comment.


Will add a comment.


>>
>>
>> As far as I tested this IP,
>> INTR__PROGRAM_COMP is set only when data are written by PIO mode.
>
> It doesn't make much sense (not saying you're wrong, just that the IP
> is weird). PROG completed should be independent of the data transfer
> step. Sure it happens after transferring data to the NAND, but then you
> still have to execute the PAGEPROG command and wait until the NAND
> becomes ready again. That's when I'd expect PROGRAM_COMP (or
> PROGRAM_FAIL) to be triggered.

You can do like that (execute 0x10 command separately)
by using the raw command mode.  (MODE_11)

When using high level interface of this IP,
the controller will take care of 0x80 command, address cycle,
data cycle, then 0x10 command.

Anyway, we agree this IP is strange.


>>
>>
>> I introduced PIO transfer in
>> http://patchwork.ozlabs.org/patch/772398/
>>
>> I used INTR__PROGRAM_COMP in denali_pio_write().
>>
>
> Yep, I see that.
>
>>
>>
>> >> +     int ret = 0;
>> >>
>> >>       denali->page = page;
>> >>
>> >> @@ -1038,13 +1039,13 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>> >>       if (irq_status == 0) {
>> >>               dev_err(denali->dev, "timeout on write_page (type = %d)\n",
>> >>                       raw_xfer);
>> >> -             denali->status = NAND_STATUS_FAIL;
>> >> +             ret = -EIO;
>> >>       }
>> >
>> >         if (irq_status & INTR__PROGRAM_FAIL) {
>> >                 dev_err(denali->dev, "page program failed (type = %d)\n",
>> >                         raw_xfer);
>> >                 ret = -EIO;
>> >         }
>>
>> This will be fixed anyway by
>> http://patchwork.ozlabs.org/patch/772414/
>
> Note that PROG_FAILED is quite different from a timeout (usually
> happens when a block becomes bad), so it probably deserve a specific
> error message.
>

OK.  Will consider it.




-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 07/23] mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()

[Boris Brezillon]

On Thu, 8 Jun 2017 18:43:47 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Hi Boris,
> 
> 
> 2017-06-08 16:05 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> > Le Thu, 8 Jun 2017 15:11:03 +0900,
> > Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
> >  
> >> Hi Boris,
> >>
> >>
> >> 2017-06-07 22:33 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:  
> >> > On Wed,  7 Jun 2017 20:52:16 +0900
> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >> >  
> >> >> Currently, the error handling of denali_write_page(_raw) is a bit
> >> >> complicated.  If the program command fails, NAND_STATUS_FAIL is set
> >> >> to the driver internal denali->status, then read out later by
> >> >> denali_waitfunc().
> >> >>
> >> >> We can avoid it by exploiting the nand_write_page() implementation.
> >> >> If chip->ecc.write_page(_raw) returns negative code (i.e. -EIO), it
> >> >> errors out immediately.  This gives the same result as returning
> >> >> NAND_STATUS_FAIL from chip->waitfunc.  In either way, -EIO is
> >> >> returned to the upper MTD layer.  
> >> >
> >> > Actually, this is how it's supposed to work now (when they set
> >> > the NAND_ECC_CUSTOM_PAGE_ACCESS flag, drivers are expected to wait for
> >> > the program operation to finish and return -EIO if it failed), so you're
> >> > all good ;-).
> >> >  
> >> >>
> >> >> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> >> >> ---
> >> >>
> >> >> Changes in v5: None
> >> >> Changes in v4: None
> >> >> Changes in v3: None
> >> >> Changes in v2:
> >> >>   - Newly added
> >> >>
> >> >>  drivers/mtd/nand/denali.c | 12 ++++--------
> >> >>  drivers/mtd/nand/denali.h |  1 -
> >> >>  2 files changed, 4 insertions(+), 9 deletions(-)
> >> >>
> >> >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> >> >> index 1897fe238290..22acfc34b546 100644
> >> >> --- a/drivers/mtd/nand/denali.c
> >> >> +++ b/drivers/mtd/nand/denali.c
> >> >> @@ -1005,6 +1005,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
> >> >>       size_t size = mtd->writesize + mtd->oobsize;
> >> >>       uint32_t irq_status;
> >> >>       uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;  
> >> >
> >> > As mentioned in my previous patch, I think you should wait for
> >> > INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL here.  
> >>
> >> No.
> >> It is intentional to use INTR__DMA_CMD_COMP
> >> instead of INTR__PROGRAM_COMP here.
> >>
> >>
> >> This is very strange of this IP,
> >> INTR__PROGRAM_COMP is never set when DMA mode is being used.
> >> (INTR__DMA_CMD_COMP is set instead.)  
> >
> > Indeed, this is really strange. Are you sure the page is actually
> > programmed when you receive the INTR__DMA_CMD_COMP interrupt?  
> 
> Yes.
> After my test, I concluded INTR__DMA_CMD_COMP is asserted
> when page program is completed.
> 
> 
> 
> Rationale:
> 
> Denali User's Guide describes the IRQ bits as follows:
> 
> 
> Bit 2 (dma_cmd_comp)    A data DMA command has completed on this bank
>   ...
> Bit 7 (program_comp)    Device finished the last issued program command
>   ...
> Bit 12 (INT_act)        R/B pin of device transitioned from low to high
>   ...
> Bit 15 (page_xfer_inc)  For every page of data transfer to or from the device,
>                         this bit will be set.
> 
> 
> 
> In my test,  ->write_page() hook triggers IRQ bits as follows:
> 
>  - Write access with DMA
>       bit 15 is asserted first,
>       then some timer later  bit 12 and bit 2 are asserted at the same time
> 
>  - Write access with PIO
>       bit 15 is asserted first,
>       then some time later   bit 12 and bit 7 are asserted at the same time
> 
> 
> 
> NAND devices toggle R/B# pin when page program is completed.
> So, bit 2 (dma_cmd_comp) means the completion of page program.
> 
> 
> I assume your next question here.
> "So, why don't you wait for INTR__INT_ACT
> instead of INTR__DMA_CMD_COMP / INTR__PROGRAM_COMP?
> It should work regardless of transfer mode."
> This has a point.
> We can always check R/B# transition for read, write, erase, or whatever.
> This is just a matter of taste, but I am just keeping code that uses
> dedicated IRQ bits for each mode.

Actually, I agree with you: it's clearer to use the INTR__DMA_CMD_COMP /
INTR__PROGRAM_COMP events here :P.

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Masahiro Yamada]

Hi Boris,


2017-06-08 16:12 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> Le Thu, 8 Jun 2017 15:10:18 +0900,
> Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
>
>> Hi Boris,
>>
>>
>> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> > On Wed,  7 Jun 2017 20:52:19 +0900
>> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >
>> >
>> >> -/*
>> >> - * This is the interrupt service routine. It handles all interrupts
>> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
>> >> - */
>> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
>> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
>> >> +                                 uint32_t irq_mask)
>> >>  {
>> >> -     struct denali_nand_info *denali = dev_id;
>> >> +     unsigned long time_left, flags;
>> >>       uint32_t irq_status;
>> >> -     irqreturn_t result = IRQ_NONE;
>> >>
>> >> -     spin_lock(&denali->irq_lock);
>> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
>> >>
>> >> -     /* check to see if a valid NAND chip has been selected. */
>> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
>> >> -             /*
>> >> -              * check to see if controller generated the interrupt,
>> >> -              * since this is a shared interrupt
>> >> -              */
>> >> -             irq_status = denali_irq_detected(denali);
>> >> -             if (irq_status != 0) {
>> >> -                     /* handle interrupt */
>> >> -                     /* first acknowledge it */
>> >> -                     clear_interrupt(denali, irq_status);
>> >> -                     /*
>> >> -                      * store the status in the device context for someone
>> >> -                      * to read
>> >> -                      */
>> >> -                     denali->irq_status |= irq_status;
>> >> -                     /* notify anyone who cares that it happened */
>> >> -                     complete(&denali->complete);
>> >> -                     /* tell the OS that we've handled this */
>> >> -                     result = IRQ_HANDLED;
>> >> -             }
>> >> +     irq_status = denali->irq_status;
>> >> +
>> >> +     if (irq_mask & irq_status) {
>> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
>> >> +             return irq_status;
>> >>       }
>> >> -     spin_unlock(&denali->irq_lock);
>> >> -     return result;
>> >> +
>> >> +     denali->irq_mask = irq_mask;
>> >> +     reinit_completion(&denali->complete);
>> >
>> > These 2 instructions should be done before calling
>> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
>> > you might loose events if they happen between your irq_status read and
>> > the reinit_completion() call.
>>
>> No.
>>
>> denali->irq_lock avoids a race between denali_isr() and
>> denali_wait_for_irq().
>>
>>
>> The line
>>      denali->irq_status |= irq_status;
>> in denali_isr() accumulates all events that have happened
>> since denali_reset_irq().
>>
>> If the interested IRQs have already happened
>> before denali_wait_for_irq(), it just return immediately
>> without using completion.
>>
>> I do not mind adding a comment like below
>> if you think my intention is unclear, though.
>>
>>         /* Return immediately if interested IRQs have already happend. */
>>         if (irq_mask & irq_status) {
>>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
>>                 return irq_status;
>>         }
>>
>>
>
> My bad, I didn't notice you were releasing the lock after calling
> reinit_completion(). I still find this solution more complex than my
> proposal, but I don't care that much.


At first, I implemented exactly like you suggested;
   denali->irq_mask = irq_mask;
   reinit_completion(&denali->complete)
in denali_reset_irq().


IIRC, things were like this.

Some time later, you memtioned to use ->cmd_ctrl
instead of ->cmdfunc.

Then I had a problem when I needed to implement
denali_check_irq() in
http://patchwork.ozlabs.org/patch/772395/

denali_wait_for_irq() is blocked until interested IRQ happens.
but ->dev_ready() hook should not be blocked.
It should return if R/B# transition has happened or not.
So, I accumulate IRQ events in denali->irq_status
that have happened since denali_reset_irq().



>>
>>
>>
>> > You should also clear existing interrupts
>> > before launching your operation, otherwise you might wakeup on previous
>> > events.
>>
>>
>> I do not see a point in your suggestion.
>>
>> denali_isr() reads out IRQ_STATUS(i) and immediately clears IRQ bits.
>>
>> IRQ events triggered by previous events are accumulated in denali->irq_status.
>>
>> denali_reset_irq() clears it.
>>
>>         denali->irq_status = 0;
>
> Well, it was just a precaution, in case some interrupts weren't cleared
> during the previous test (for example if they were masked before the
> event actually happened, which can occur if you have a timeout, but
> the event is detected afterward).

Turning on/off IRQ mask is problematic.
So I did not do that.

I enable IRQ mask in driver probe.
I think this approach is more robust when we consider race conditions
like you mentioned.

>>
>>
>> Again, denali->irq_lock avoids a race between denali_reset_irq() and
>> denali_irq(),
>> so this works correctly.
>>
>>
>
> Anyway, you seem confident that you're doing the right thing, so I'll
> let you decide what is appropriate and redirect any bug report to you if
> that happens :-P.

Yeah.

I came up with this solution after my long thought and efforts,
so I'd like to go with this.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 19/23] mtd: nand: denali: fix raw and oob accessors for syndrome page layout

[Masahiro Yamada]

2017-06-07 23:09 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Wed,  7 Jun 2017 20:52:28 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>>
>> +static void denali_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
>> +{
>> +     struct denali_nand_info *denali = mtd_to_denali(mtd);
>> +     int i;
>> +
>> +     iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);
>
> What is this '| 2'? You seem to use it a lot. Can you define a macro
> and maybe add a comment if the macro name is not self-descriptive.

The type of access.

bit[1:0] == 0   : command cycle
            1   : address cycle
            2   : data read/write cycle

I will replace magic numbers
with macros or something.



-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Boris Brezillon]

On Thu, 8 Jun 2017 19:41:39 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Hi Boris,
> 
> 
> 2017-06-08 16:12 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> > Le Thu, 8 Jun 2017 15:10:18 +0900,
> > Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
> >  
> >> Hi Boris,
> >>
> >>
> >> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:  
> >> > On Wed,  7 Jun 2017 20:52:19 +0900
> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >> >
> >> >  
> >> >> -/*
> >> >> - * This is the interrupt service routine. It handles all interrupts
> >> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
> >> >> - */
> >> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
> >> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
> >> >> +                                 uint32_t irq_mask)
> >> >>  {
> >> >> -     struct denali_nand_info *denali = dev_id;
> >> >> +     unsigned long time_left, flags;
> >> >>       uint32_t irq_status;
> >> >> -     irqreturn_t result = IRQ_NONE;
> >> >>
> >> >> -     spin_lock(&denali->irq_lock);
> >> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
> >> >>
> >> >> -     /* check to see if a valid NAND chip has been selected. */
> >> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
> >> >> -             /*
> >> >> -              * check to see if controller generated the interrupt,
> >> >> -              * since this is a shared interrupt
> >> >> -              */
> >> >> -             irq_status = denali_irq_detected(denali);
> >> >> -             if (irq_status != 0) {
> >> >> -                     /* handle interrupt */
> >> >> -                     /* first acknowledge it */
> >> >> -                     clear_interrupt(denali, irq_status);
> >> >> -                     /*
> >> >> -                      * store the status in the device context for someone
> >> >> -                      * to read
> >> >> -                      */
> >> >> -                     denali->irq_status |= irq_status;
> >> >> -                     /* notify anyone who cares that it happened */
> >> >> -                     complete(&denali->complete);
> >> >> -                     /* tell the OS that we've handled this */
> >> >> -                     result = IRQ_HANDLED;
> >> >> -             }
> >> >> +     irq_status = denali->irq_status;
> >> >> +
> >> >> +     if (irq_mask & irq_status) {
> >> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
> >> >> +             return irq_status;
> >> >>       }
> >> >> -     spin_unlock(&denali->irq_lock);
> >> >> -     return result;
> >> >> +
> >> >> +     denali->irq_mask = irq_mask;
> >> >> +     reinit_completion(&denali->complete);  
> >> >
> >> > These 2 instructions should be done before calling
> >> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
> >> > you might loose events if they happen between your irq_status read and
> >> > the reinit_completion() call.  
> >>
> >> No.
> >>
> >> denali->irq_lock avoids a race between denali_isr() and
> >> denali_wait_for_irq().
> >>
> >>
> >> The line
> >>      denali->irq_status |= irq_status;
> >> in denali_isr() accumulates all events that have happened
> >> since denali_reset_irq().
> >>
> >> If the interested IRQs have already happened
> >> before denali_wait_for_irq(), it just return immediately
> >> without using completion.
> >>
> >> I do not mind adding a comment like below
> >> if you think my intention is unclear, though.
> >>
> >>         /* Return immediately if interested IRQs have already happend. */
> >>         if (irq_mask & irq_status) {
> >>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
> >>                 return irq_status;
> >>         }
> >>
> >>  
> >
> > My bad, I didn't notice you were releasing the lock after calling
> > reinit_completion(). I still find this solution more complex than my
> > proposal, but I don't care that much.  
> 
> 
> At first, I implemented exactly like you suggested;
>    denali->irq_mask = irq_mask;
>    reinit_completion(&denali->complete)
> in denali_reset_irq().
> 
> 
> IIRC, things were like this.
> 
> Some time later, you memtioned to use ->cmd_ctrl
> instead of ->cmdfunc.
> 
> Then I had a problem when I needed to implement
> denali_check_irq() in
> http://patchwork.ozlabs.org/patch/772395/
> 
> denali_wait_for_irq() is blocked until interested IRQ happens.
> but ->dev_ready() hook should not be blocked.
> It should return if R/B# transition has happened or not.

Nope, it should return whether the NAND is ready or not, not whether a
busy -> ready transition occurred or not. It's typically done by
reading the NAND STATUS register or by checking the R/B pin status.

> So, I accumulate IRQ events in denali->irq_status
> that have happened since denali_reset_irq().

Yep, I see that.

> 
> 
> 
> >>
> >>
> >>  
> >> > You should also clear existing interrupts
> >> > before launching your operation, otherwise you might wakeup on previous
> >> > events.  
> >>
> >>
> >> I do not see a point in your suggestion.
> >>
> >> denali_isr() reads out IRQ_STATUS(i) and immediately clears IRQ bits.
> >>
> >> IRQ events triggered by previous events are accumulated in denali->irq_status.
> >>
> >> denali_reset_irq() clears it.
> >>
> >>         denali->irq_status = 0;  
> >
> > Well, it was just a precaution, in case some interrupts weren't cleared
> > during the previous test (for example if they were masked before the
> > event actually happened, which can occur if you have a timeout, but
> > the event is detected afterward).  
> 
> Turning on/off IRQ mask is problematic.
> So I did not do that.

I don't see why this is a problem. That's how it usually done.

> 
> I enable IRQ mask in driver probe.
> I think this approach is more robust when we consider race conditions
> like you mentioned.

I'd like to hear more about the reasons you think it's more robust
than

* at-probe-time: mask all IRQs and reset IRQ status

* when doing a specific operation:
1/ reset irq status
2/ unmask relevant irqs (based on the operation you're doing)
3/ launch the operation
4/ wait for interrupts
5/ mask irqs and check the wait_for_completion() return code + irq
   status

This approach shouldn't be racy, because you're resetting+unmasking
irqs before starting the real operation (the one supposed to generate
such interrupts). By doing that you also get rid of the extra
->irq_status field, and you don't have to check irq_status before
calling wait_for_completion().

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Masahiro Yamada]

Hi Boris,

2017-06-08 20:26 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Thu, 8 Jun 2017 19:41:39 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> Hi Boris,
>>
>>
>> 2017-06-08 16:12 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> > Le Thu, 8 Jun 2017 15:10:18 +0900,
>> > Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
>> >
>> >> Hi Boris,
>> >>
>> >>
>> >> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> >> > On Wed,  7 Jun 2017 20:52:19 +0900
>> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >> >
>> >> >
>> >> >> -/*
>> >> >> - * This is the interrupt service routine. It handles all interrupts
>> >> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
>> >> >> - */
>> >> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
>> >> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
>> >> >> +                                 uint32_t irq_mask)
>> >> >>  {
>> >> >> -     struct denali_nand_info *denali = dev_id;
>> >> >> +     unsigned long time_left, flags;
>> >> >>       uint32_t irq_status;
>> >> >> -     irqreturn_t result = IRQ_NONE;
>> >> >>
>> >> >> -     spin_lock(&denali->irq_lock);
>> >> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
>> >> >>
>> >> >> -     /* check to see if a valid NAND chip has been selected. */
>> >> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
>> >> >> -             /*
>> >> >> -              * check to see if controller generated the interrupt,
>> >> >> -              * since this is a shared interrupt
>> >> >> -              */
>> >> >> -             irq_status = denali_irq_detected(denali);
>> >> >> -             if (irq_status != 0) {
>> >> >> -                     /* handle interrupt */
>> >> >> -                     /* first acknowledge it */
>> >> >> -                     clear_interrupt(denali, irq_status);
>> >> >> -                     /*
>> >> >> -                      * store the status in the device context for someone
>> >> >> -                      * to read
>> >> >> -                      */
>> >> >> -                     denali->irq_status |= irq_status;
>> >> >> -                     /* notify anyone who cares that it happened */
>> >> >> -                     complete(&denali->complete);
>> >> >> -                     /* tell the OS that we've handled this */
>> >> >> -                     result = IRQ_HANDLED;
>> >> >> -             }
>> >> >> +     irq_status = denali->irq_status;
>> >> >> +
>> >> >> +     if (irq_mask & irq_status) {
>> >> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
>> >> >> +             return irq_status;
>> >> >>       }
>> >> >> -     spin_unlock(&denali->irq_lock);
>> >> >> -     return result;
>> >> >> +
>> >> >> +     denali->irq_mask = irq_mask;
>> >> >> +     reinit_completion(&denali->complete);
>> >> >
>> >> > These 2 instructions should be done before calling
>> >> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
>> >> > you might loose events if they happen between your irq_status read and
>> >> > the reinit_completion() call.
>> >>
>> >> No.
>> >>
>> >> denali->irq_lock avoids a race between denali_isr() and
>> >> denali_wait_for_irq().
>> >>
>> >>
>> >> The line
>> >>      denali->irq_status |= irq_status;
>> >> in denali_isr() accumulates all events that have happened
>> >> since denali_reset_irq().
>> >>
>> >> If the interested IRQs have already happened
>> >> before denali_wait_for_irq(), it just return immediately
>> >> without using completion.
>> >>
>> >> I do not mind adding a comment like below
>> >> if you think my intention is unclear, though.
>> >>
>> >>         /* Return immediately if interested IRQs have already happend. */
>> >>         if (irq_mask & irq_status) {
>> >>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
>> >>                 return irq_status;
>> >>         }
>> >>
>> >>
>> >
>> > My bad, I didn't notice you were releasing the lock after calling
>> > reinit_completion(). I still find this solution more complex than my
>> > proposal, but I don't care that much.
>>
>>
>> At first, I implemented exactly like you suggested;
>>    denali->irq_mask = irq_mask;
>>    reinit_completion(&denali->complete)
>> in denali_reset_irq().
>>
>>
>> IIRC, things were like this.
>>
>> Some time later, you memtioned to use ->cmd_ctrl
>> instead of ->cmdfunc.
>>
>> Then I had a problem when I needed to implement
>> denali_check_irq() in
>> http://patchwork.ozlabs.org/patch/772395/
>>
>> denali_wait_for_irq() is blocked until interested IRQ happens.
>> but ->dev_ready() hook should not be blocked.
>> It should return if R/B# transition has happened or not.
>
> Nope, it should return whether the NAND is ready or not, not whether a
> busy -> ready transition occurred or not. It's typically done by
> reading the NAND STATUS register or by checking the R/B pin status.

Checking the R/B pin is probably impossible unless
the pin is changed into a GPIO port.

I also considered NAND_CMD_STATUS, but
I can not recall why I chose the current approach.
Perhaps I thought returning detected IRQ
is faster than accessing the chip for NAND_CMD_STATUS.

I can try NAND_CMD_STATUS approach if you like.





>> So, I accumulate IRQ events in denali->irq_status
>> that have happened since denali_reset_irq().
>
> Yep, I see that.
>
>>
>>
>>
>> >>
>> >>
>> >>
>> >> > You should also clear existing interrupts
>> >> > before launching your operation, otherwise you might wakeup on previous
>> >> > events.
>> >>
>> >>
>> >> I do not see a point in your suggestion.
>> >>
>> >> denali_isr() reads out IRQ_STATUS(i) and immediately clears IRQ bits.
>> >>
>> >> IRQ events triggered by previous events are accumulated in denali->irq_status.
>> >>
>> >> denali_reset_irq() clears it.
>> >>
>> >>         denali->irq_status = 0;
>> >
>> > Well, it was just a precaution, in case some interrupts weren't cleared
>> > during the previous test (for example if they were masked before the
>> > event actually happened, which can occur if you have a timeout, but
>> > the event is detected afterward).
>>
>> Turning on/off IRQ mask is problematic.
>> So I did not do that.
>
> I don't see why this is a problem. That's how it usually done.
>
>>
>> I enable IRQ mask in driver probe.
>> I think this approach is more robust when we consider race conditions
>> like you mentioned.
>
> I'd like to hear more about the reasons you think it's more robust
> than
>
> * at-probe-time: mask all IRQs and reset IRQ status
>
> * when doing a specific operation:
> 1/ reset irq status
> 2/ unmask relevant irqs (based on the operation you're doing)
> 3/ launch the operation
> 4/ wait for interrupts
> 5/ mask irqs and check the wait_for_completion() return code + irq
>    status
>
> This approach shouldn't be racy, because you're resetting+unmasking
> irqs before starting the real operation (the one supposed to generate
> such interrupts). By doing that you also get rid of the extra
> ->irq_status field, and you don't have to check irq_status before
> calling wait_for_completion().


IIRC, I was thinking like this:

One IRQ line may be shared among multiple hardware including Denali.
denali_pci may do this.

The Denali IRQ handler need to check irq status
because it should return IRQ_HANDLED if the event comes from Denali controller.
Otherwise, the event comes from different hardware, so
Denali IRQ handler should return IRQ_NONE.

wait_for_completion_timeout() may bail out with timeout error,
then proceed to denali_reset_irq() for the next operation.
Afterwards, the event actually may happen, and invoke IRQ handler.

denali_reset_irq() and denali_isr() compete to grab the spin lock.

If denali_reset_irq() wins, it clears INTR_STATUS register
(if implemented like you suggested first) or changes IRQ mask for the
next event.
After that, denali_isr enters the critical section and checks IRQ bit
but at this moment, the IRQ bit has gone.  So, it assumes this event
is not for Denali, so returns IRQ_NONE.  Nobody returns IRQ_HANDLED.

Then, kernel will complain "irq *: nobody cared"


In my opinion, IRQ should be checked and cleared in one place
(in IRQ handler).

Enabling/disabling IRQ mask is not problem unless it masks out
already-asserted IRQ status bits.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Boris Brezillon]

On Thu, 8 Jun 2017 21:58:00 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Hi Boris,
> 
> 2017-06-08 20:26 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> > On Thu, 8 Jun 2017 19:41:39 +0900
> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >  
> >> Hi Boris,
> >>
> >>
> >> 2017-06-08 16:12 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:  
> >> > Le Thu, 8 Jun 2017 15:10:18 +0900,
> >> > Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
> >> >  
> >> >> Hi Boris,
> >> >>
> >> >>
> >> >> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:  
> >> >> > On Wed,  7 Jun 2017 20:52:19 +0900
> >> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >> >> >
> >> >> >  
> >> >> >> -/*
> >> >> >> - * This is the interrupt service routine. It handles all interrupts
> >> >> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
> >> >> >> - */
> >> >> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
> >> >> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
> >> >> >> +                                 uint32_t irq_mask)
> >> >> >>  {
> >> >> >> -     struct denali_nand_info *denali = dev_id;
> >> >> >> +     unsigned long time_left, flags;
> >> >> >>       uint32_t irq_status;
> >> >> >> -     irqreturn_t result = IRQ_NONE;
> >> >> >>
> >> >> >> -     spin_lock(&denali->irq_lock);
> >> >> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
> >> >> >>
> >> >> >> -     /* check to see if a valid NAND chip has been selected. */
> >> >> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
> >> >> >> -             /*
> >> >> >> -              * check to see if controller generated the interrupt,
> >> >> >> -              * since this is a shared interrupt
> >> >> >> -              */
> >> >> >> -             irq_status = denali_irq_detected(denali);
> >> >> >> -             if (irq_status != 0) {
> >> >> >> -                     /* handle interrupt */
> >> >> >> -                     /* first acknowledge it */
> >> >> >> -                     clear_interrupt(denali, irq_status);
> >> >> >> -                     /*
> >> >> >> -                      * store the status in the device context for someone
> >> >> >> -                      * to read
> >> >> >> -                      */
> >> >> >> -                     denali->irq_status |= irq_status;
> >> >> >> -                     /* notify anyone who cares that it happened */
> >> >> >> -                     complete(&denali->complete);
> >> >> >> -                     /* tell the OS that we've handled this */
> >> >> >> -                     result = IRQ_HANDLED;
> >> >> >> -             }
> >> >> >> +     irq_status = denali->irq_status;
> >> >> >> +
> >> >> >> +     if (irq_mask & irq_status) {
> >> >> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
> >> >> >> +             return irq_status;
> >> >> >>       }
> >> >> >> -     spin_unlock(&denali->irq_lock);
> >> >> >> -     return result;
> >> >> >> +
> >> >> >> +     denali->irq_mask = irq_mask;
> >> >> >> +     reinit_completion(&denali->complete);  
> >> >> >
> >> >> > These 2 instructions should be done before calling
> >> >> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
> >> >> > you might loose events if they happen between your irq_status read and
> >> >> > the reinit_completion() call.  
> >> >>
> >> >> No.
> >> >>
> >> >> denali->irq_lock avoids a race between denali_isr() and
> >> >> denali_wait_for_irq().
> >> >>
> >> >>
> >> >> The line
> >> >>      denali->irq_status |= irq_status;
> >> >> in denali_isr() accumulates all events that have happened
> >> >> since denali_reset_irq().
> >> >>
> >> >> If the interested IRQs have already happened
> >> >> before denali_wait_for_irq(), it just return immediately
> >> >> without using completion.
> >> >>
> >> >> I do not mind adding a comment like below
> >> >> if you think my intention is unclear, though.
> >> >>
> >> >>         /* Return immediately if interested IRQs have already happend. */
> >> >>         if (irq_mask & irq_status) {
> >> >>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
> >> >>                 return irq_status;
> >> >>         }
> >> >>
> >> >>  
> >> >
> >> > My bad, I didn't notice you were releasing the lock after calling
> >> > reinit_completion(). I still find this solution more complex than my
> >> > proposal, but I don't care that much.  
> >>
> >>
> >> At first, I implemented exactly like you suggested;
> >>    denali->irq_mask = irq_mask;
> >>    reinit_completion(&denali->complete)
> >> in denali_reset_irq().
> >>
> >>
> >> IIRC, things were like this.
> >>
> >> Some time later, you memtioned to use ->cmd_ctrl
> >> instead of ->cmdfunc.
> >>
> >> Then I had a problem when I needed to implement
> >> denali_check_irq() in
> >> http://patchwork.ozlabs.org/patch/772395/
> >>
> >> denali_wait_for_irq() is blocked until interested IRQ happens.
> >> but ->dev_ready() hook should not be blocked.
> >> It should return if R/B# transition has happened or not.  
> >
> > Nope, it should return whether the NAND is ready or not, not whether a
> > busy -> ready transition occurred or not. It's typically done by
> > reading the NAND STATUS register or by checking the R/B pin status.  
> 
> Checking the R/B pin is probably impossible unless
> the pin is changed into a GPIO port.
> 
> I also considered NAND_CMD_STATUS, but
> I can not recall why I chose the current approach.
> Perhaps I thought returning detected IRQ
> is faster than accessing the chip for NAND_CMD_STATUS.
> 
> I can try NAND_CMD_STATUS approach if you like.

Depends what you're trying to do. IIUC, you use denali_wait_for_irq()
inside your ->reset()/->read/write_{page,oob}[_raw]() methods, which is
perfectly fine (assuming CUSTOM_PAGE_ACCESS is set) since these hooks
are expected to wait for chip readiness before returning.

You could also implement ->waitfunc() using denali_wait_for_irq() if
you're able to detect R/B transitions, but I'm not sure it's worth it,
because you overload almost all the methods using this hook (the only
one remaining is ->onfi_set_features(), and using STATUS polling should
not be an issue in this case).

Implementing ->dev_ready() is not necessary. When not provided, the
core falls back to STATUS polling and you seem to support
NAND_CMD_STATUS in denali_cmdfunc(). Note that even if it's not fully
reliable in the current driver, you're switching to ->cmd_ctrl() at the
end of the series anyway, so we should be good after that.

> 
> 
> 
> 
> 
> >> So, I accumulate IRQ events in denali->irq_status
> >> that have happened since denali_reset_irq().  
> >
> > Yep, I see that.
> >  
> >>
> >>
> >>  
> >> >>
> >> >>
> >> >>  
> >> >> > You should also clear existing interrupts
> >> >> > before launching your operation, otherwise you might wakeup on previous
> >> >> > events.  
> >> >>
> >> >>
> >> >> I do not see a point in your suggestion.
> >> >>
> >> >> denali_isr() reads out IRQ_STATUS(i) and immediately clears IRQ bits.
> >> >>
> >> >> IRQ events triggered by previous events are accumulated in denali->irq_status.
> >> >>
> >> >> denali_reset_irq() clears it.
> >> >>
> >> >>         denali->irq_status = 0;  
> >> >
> >> > Well, it was just a precaution, in case some interrupts weren't cleared
> >> > during the previous test (for example if they were masked before the
> >> > event actually happened, which can occur if you have a timeout, but
> >> > the event is detected afterward).  
> >>
> >> Turning on/off IRQ mask is problematic.
> >> So I did not do that.  
> >
> > I don't see why this is a problem. That's how it usually done.
> >  
> >>
> >> I enable IRQ mask in driver probe.
> >> I think this approach is more robust when we consider race conditions
> >> like you mentioned.  
> >
> > I'd like to hear more about the reasons you think it's more robust
> > than
> >
> > * at-probe-time: mask all IRQs and reset IRQ status
> >
> > * when doing a specific operation:
> > 1/ reset irq status
> > 2/ unmask relevant irqs (based on the operation you're doing)
> > 3/ launch the operation
> > 4/ wait for interrupts
> > 5/ mask irqs and check the wait_for_completion() return code + irq
> >    status
> >
> > This approach shouldn't be racy, because you're resetting+unmasking
> > irqs before starting the real operation (the one supposed to generate
> > such interrupts). By doing that you also get rid of the extra  
> > ->irq_status field, and you don't have to check irq_status before  
> > calling wait_for_completion().  
> 
> 
> IIRC, I was thinking like this:
> 
> One IRQ line may be shared among multiple hardware including Denali.
> denali_pci may do this.
> 
> The Denali IRQ handler need to check irq status
> because it should return IRQ_HANDLED if the event comes from Denali controller.
> Otherwise, the event comes from different hardware, so
> Denali IRQ handler should return IRQ_NONE.

Correct.

> 
> wait_for_completion_timeout() may bail out with timeout error,
> then proceed to denali_reset_irq() for the next operation.

Before calling denali_reset_irq() you should re-mask the irqs you
unmasked in #1. Actually, calling denali_reset_irq() after
wait_for_completion_timeout() is not even needed here because you'll
clear pending irqs before launching the next NAND command.

> Afterwards, the event actually may happen, and invoke IRQ handler.

Not if you masked IRQs after wait_for_completion_timeout() returned.

> 
> denali_reset_irq() and denali_isr() compete to grab the spin lock.
> 
> If denali_reset_irq() wins, it clears INTR_STATUS register
> (if implemented like you suggested first) or changes IRQ mask for the
> next event.
> After that, denali_isr enters the critical section and checks IRQ bit
> but at this moment, the IRQ bit has gone.  So, it assumes this event
> is not for Denali, so returns IRQ_NONE.  Nobody returns IRQ_HANDLED.

Not if you have masked the interrupts.

> 
> Then, kernel will complain "irq *: nobody cared"
> 
> 
> In my opinion, IRQ should be checked and cleared in one place
> (in IRQ handler).
> 
> Enabling/disabling IRQ mask is not problem unless it masks out
> already-asserted IRQ status bits.

Here is a patch to show you what I had in mind [1] (it applies on top
of this patch). AFAICT, there's no races, no interrupt loss, and you
get rid of the ->irq_mask/status/lock fields.

[1]http://code.bulix.org/fufia6-145571

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Masahiro Yamada]

Hi Boris

2017-06-09 0:43 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Thu, 8 Jun 2017 21:58:00 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> Hi Boris,
>>
>> 2017-06-08 20:26 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> > On Thu, 8 Jun 2017 19:41:39 +0900
>> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >
>> >> Hi Boris,
>> >>
>> >>
>> >> 2017-06-08 16:12 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> >> > Le Thu, 8 Jun 2017 15:10:18 +0900,
>> >> > Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
>> >> >
>> >> >> Hi Boris,
>> >> >>
>> >> >>
>> >> >> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> >> >> > On Wed,  7 Jun 2017 20:52:19 +0900
>> >> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >> >> >
>> >> >> >
>> >> >> >> -/*
>> >> >> >> - * This is the interrupt service routine. It handles all interrupts
>> >> >> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
>> >> >> >> - */
>> >> >> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
>> >> >> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
>> >> >> >> +                                 uint32_t irq_mask)
>> >> >> >>  {
>> >> >> >> -     struct denali_nand_info *denali = dev_id;
>> >> >> >> +     unsigned long time_left, flags;
>> >> >> >>       uint32_t irq_status;
>> >> >> >> -     irqreturn_t result = IRQ_NONE;
>> >> >> >>
>> >> >> >> -     spin_lock(&denali->irq_lock);
>> >> >> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
>> >> >> >>
>> >> >> >> -     /* check to see if a valid NAND chip has been selected. */
>> >> >> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
>> >> >> >> -             /*
>> >> >> >> -              * check to see if controller generated the interrupt,
>> >> >> >> -              * since this is a shared interrupt
>> >> >> >> -              */
>> >> >> >> -             irq_status = denali_irq_detected(denali);
>> >> >> >> -             if (irq_status != 0) {
>> >> >> >> -                     /* handle interrupt */
>> >> >> >> -                     /* first acknowledge it */
>> >> >> >> -                     clear_interrupt(denali, irq_status);
>> >> >> >> -                     /*
>> >> >> >> -                      * store the status in the device context for someone
>> >> >> >> -                      * to read
>> >> >> >> -                      */
>> >> >> >> -                     denali->irq_status |= irq_status;
>> >> >> >> -                     /* notify anyone who cares that it happened */
>> >> >> >> -                     complete(&denali->complete);
>> >> >> >> -                     /* tell the OS that we've handled this */
>> >> >> >> -                     result = IRQ_HANDLED;
>> >> >> >> -             }
>> >> >> >> +     irq_status = denali->irq_status;
>> >> >> >> +
>> >> >> >> +     if (irq_mask & irq_status) {
>> >> >> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
>> >> >> >> +             return irq_status;
>> >> >> >>       }
>> >> >> >> -     spin_unlock(&denali->irq_lock);
>> >> >> >> -     return result;
>> >> >> >> +
>> >> >> >> +     denali->irq_mask = irq_mask;
>> >> >> >> +     reinit_completion(&denali->complete);
>> >> >> >
>> >> >> > These 2 instructions should be done before calling
>> >> >> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
>> >> >> > you might loose events if they happen between your irq_status read and
>> >> >> > the reinit_completion() call.
>> >> >>
>> >> >> No.
>> >> >>
>> >> >> denali->irq_lock avoids a race between denali_isr() and
>> >> >> denali_wait_for_irq().
>> >> >>
>> >> >>
>> >> >> The line
>> >> >>      denali->irq_status |= irq_status;
>> >> >> in denali_isr() accumulates all events that have happened
>> >> >> since denali_reset_irq().
>> >> >>
>> >> >> If the interested IRQs have already happened
>> >> >> before denali_wait_for_irq(), it just return immediately
>> >> >> without using completion.
>> >> >>
>> >> >> I do not mind adding a comment like below
>> >> >> if you think my intention is unclear, though.
>> >> >>
>> >> >>         /* Return immediately if interested IRQs have already happend. */
>> >> >>         if (irq_mask & irq_status) {
>> >> >>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
>> >> >>                 return irq_status;
>> >> >>         }
>> >> >>
>> >> >>
>> >> >
>> >> > My bad, I didn't notice you were releasing the lock after calling
>> >> > reinit_completion(). I still find this solution more complex than my
>> >> > proposal, but I don't care that much.
>> >>
>> >>
>> >> At first, I implemented exactly like you suggested;
>> >>    denali->irq_mask = irq_mask;
>> >>    reinit_completion(&denali->complete)
>> >> in denali_reset_irq().
>> >>
>> >>
>> >> IIRC, things were like this.
>> >>
>> >> Some time later, you memtioned to use ->cmd_ctrl
>> >> instead of ->cmdfunc.
>> >>
>> >> Then I had a problem when I needed to implement
>> >> denali_check_irq() in
>> >> http://patchwork.ozlabs.org/patch/772395/
>> >>
>> >> denali_wait_for_irq() is blocked until interested IRQ happens.
>> >> but ->dev_ready() hook should not be blocked.
>> >> It should return if R/B# transition has happened or not.
>> >
>> > Nope, it should return whether the NAND is ready or not, not whether a
>> > busy -> ready transition occurred or not. It's typically done by
>> > reading the NAND STATUS register or by checking the R/B pin status.
>>
>> Checking the R/B pin is probably impossible unless
>> the pin is changed into a GPIO port.
>>
>> I also considered NAND_CMD_STATUS, but
>> I can not recall why I chose the current approach.
>> Perhaps I thought returning detected IRQ
>> is faster than accessing the chip for NAND_CMD_STATUS.
>>
>> I can try NAND_CMD_STATUS approach if you like.
>
> Depends what you're trying to do. IIUC, you use denali_wait_for_irq()
> inside your ->reset()/->read/write_{page,oob}[_raw]() methods, which is
> perfectly fine (assuming CUSTOM_PAGE_ACCESS is set) since these hooks
> are expected to wait for chip readiness before returning.
>
> You could also implement ->waitfunc() using denali_wait_for_irq() if
> you're able to detect R/B transitions,

R/B transition will set INTR__INT_ACT interrupt.

I think it is easy in my implementation of denali_wait_for_irq(),
like

   denali_wait_for_irq(denali, INTR__INT_ACT);



But, you are suggesting me to change it.
In your way, you give IRQ masks to denali_reset_irq(), like
denali_reset_irq(denali, INTR__ERASE_COMP | INTR__ERASE_FAIL);

Then, we have no room of IRQ bit in denali_wait_for_irq().

How will you implement it?







> but I'm not sure it's worth it,
> because you overload almost all the methods using this hook (the only
> one remaining is ->onfi_set_features(), and using STATUS polling should
> not be an issue in this case).
>
> Implementing ->dev_ready() is not necessary. When not provided, the
> core falls back to STATUS polling and you seem to support
> NAND_CMD_STATUS in denali_cmdfunc(). Note that even if it's not fully
> reliable in the current driver, you're switching to ->cmd_ctrl() at the
> end of the series anyway, so we should be good after that.

->dev_ready() is optional, but we may end up with waiting more than needed.

        case NAND_CMD_RESET:
                if (chip->dev_ready)
                         break;
                udelay(chip->chip_delay);


chip->chip_delay is probably set large enough, so this is not optimal.




If I add something more, the following two bugs were found by
denali_dev_ready().

commit 3158fa0e739615769cc047d2428f30f4c3b6640e
commit c5d664aa5a4c4b257a54eb35045031630d105f49


If NAND core is fine, denali_dev_ready() works fine too.

If not, it is a sign of bug of nand_command(_lp).
This is contributing to the core improvement.





>>
>> IIRC, I was thinking like this:
>>
>> One IRQ line may be shared among multiple hardware including Denali.
>> denali_pci may do this.
>>
>> The Denali IRQ handler need to check irq status
>> because it should return IRQ_HANDLED if the event comes from Denali controller.
>> Otherwise, the event comes from different hardware, so
>> Denali IRQ handler should return IRQ_NONE.
>
> Correct.
>
>>
>> wait_for_completion_timeout() may bail out with timeout error,
>> then proceed to denali_reset_irq() for the next operation.
>
> Before calling denali_reset_irq() you should re-mask the irqs you
> unmasked in #1. Actually, calling denali_reset_irq() after
> wait_for_completion_timeout() is not even needed here because you'll
> clear pending irqs before launching the next NAND command.
>
>> Afterwards, the event actually may happen, and invoke IRQ handler.
>
> Not if you masked IRQs after wait_for_completion_timeout() returned.


        wait_for_completion_timeout(&denali->complete, msecs_to_jiffies(1000));
                <<< WHAT IF IRQ EVENT HAPPENS HERE ? >>>
        iowrite32(0, denali->flash_reg + INTR_EN(denali->flash_bank));




Also, you ignore the return value of wait_for_completion_timeout(),
then drop my precious error message()

  dev_err(denali->dev, "timeout while waiting for irq 0x%x\n",
          denali->irq_mask)



> Here is a patch to show you what I had in mind [1] (it applies on top
> of this patch). AFAICT, there's no races, no interrupt loss, and you
> get rid of the ->irq_mask/status/lock fields.
>
> [1]http://code.bulix.org/fufia6-145571
>


Problem Scenario A
 [1] wait_for_completion_timeout() exits with timeout.
 [2] IRQ happens and denali_isr() is invoked
 [3] iowrite32(0, denali->flash_reg + INTR_EN(denali->flash_bank));
 [4] status = ioread32(denali->flash_reg + INTR_STATUS(bank)) &
              ioread32(denali->flash_reg + INTR_EN(bank));
      (status is set to 0 because INTR_EN(bank) is now 0)
 [5] return IRQ_NONE;
 [6] kernel complains  "irq *: nobody cared"



Problem Scenario B  (unlikely to happen, though)
 [1] wait_for_completion_timeout() exits with timeout.
 [2] IRQ happens and denali_isr() is invoked
 [3] iowrite32(0, denali->flash_reg + INTR_EN(denali->flash_bank));
 [4] chip->select_chip(mtd, -1)
 [5] denali->flash_bank = -1
 [6] status = ioread32(denali->flash_reg + INTR_STATUS(bank)) &
              ioread32(denali->flash_reg + INTR_EN(bank));
       ( access to non-existing INTR_STATUS(-1) )





-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Masahiro Yamada]

2017-06-09 2:26 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

> ->dev_ready() is optional, but we may end up with waiting more than needed.
>
>         case NAND_CMD_RESET:
>                 if (chip->dev_ready)
>                          break;
>                 udelay(chip->chip_delay);
>
>
> chip->chip_delay is probably set large enough, so this is not optimal.

I misunderstood the code.

The following line will be the most of the part of delay.

     nand_wait_status_ready(mtd, 250);


-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Boris Brezillon]

Hi Masahiro,

On Fri, 9 Jun 2017 02:26:34 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Hi Boris
> 
> 2017-06-09 0:43 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> > On Thu, 8 Jun 2017 21:58:00 +0900
> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >  
> >> Hi Boris,
> >>
> >> 2017-06-08 20:26 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:  
> >> > On Thu, 8 Jun 2017 19:41:39 +0900
> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >> >  
> >> >> Hi Boris,
> >> >>
> >> >>
> >> >> 2017-06-08 16:12 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:  
> >> >> > Le Thu, 8 Jun 2017 15:10:18 +0900,
> >> >> > Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
> >> >> >  
> >> >> >> Hi Boris,
> >> >> >>
> >> >> >>
> >> >> >> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:  
> >> >> >> > On Wed,  7 Jun 2017 20:52:19 +0900
> >> >> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> >> >> >> >
> >> >> >> >  
> >> >> >> >> -/*
> >> >> >> >> - * This is the interrupt service routine. It handles all interrupts
> >> >> >> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
> >> >> >> >> - */
> >> >> >> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
> >> >> >> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
> >> >> >> >> +                                 uint32_t irq_mask)
> >> >> >> >>  {
> >> >> >> >> -     struct denali_nand_info *denali = dev_id;
> >> >> >> >> +     unsigned long time_left, flags;
> >> >> >> >>       uint32_t irq_status;
> >> >> >> >> -     irqreturn_t result = IRQ_NONE;
> >> >> >> >>
> >> >> >> >> -     spin_lock(&denali->irq_lock);
> >> >> >> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
> >> >> >> >>
> >> >> >> >> -     /* check to see if a valid NAND chip has been selected. */
> >> >> >> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
> >> >> >> >> -             /*
> >> >> >> >> -              * check to see if controller generated the interrupt,
> >> >> >> >> -              * since this is a shared interrupt
> >> >> >> >> -              */
> >> >> >> >> -             irq_status = denali_irq_detected(denali);
> >> >> >> >> -             if (irq_status != 0) {
> >> >> >> >> -                     /* handle interrupt */
> >> >> >> >> -                     /* first acknowledge it */
> >> >> >> >> -                     clear_interrupt(denali, irq_status);
> >> >> >> >> -                     /*
> >> >> >> >> -                      * store the status in the device context for someone
> >> >> >> >> -                      * to read
> >> >> >> >> -                      */
> >> >> >> >> -                     denali->irq_status |= irq_status;
> >> >> >> >> -                     /* notify anyone who cares that it happened */
> >> >> >> >> -                     complete(&denali->complete);
> >> >> >> >> -                     /* tell the OS that we've handled this */
> >> >> >> >> -                     result = IRQ_HANDLED;
> >> >> >> >> -             }
> >> >> >> >> +     irq_status = denali->irq_status;
> >> >> >> >> +
> >> >> >> >> +     if (irq_mask & irq_status) {
> >> >> >> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
> >> >> >> >> +             return irq_status;
> >> >> >> >>       }
> >> >> >> >> -     spin_unlock(&denali->irq_lock);
> >> >> >> >> -     return result;
> >> >> >> >> +
> >> >> >> >> +     denali->irq_mask = irq_mask;
> >> >> >> >> +     reinit_completion(&denali->complete);  
> >> >> >> >
> >> >> >> > These 2 instructions should be done before calling
> >> >> >> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
> >> >> >> > you might loose events if they happen between your irq_status read and
> >> >> >> > the reinit_completion() call.  
> >> >> >>
> >> >> >> No.
> >> >> >>
> >> >> >> denali->irq_lock avoids a race between denali_isr() and
> >> >> >> denali_wait_for_irq().
> >> >> >>
> >> >> >>
> >> >> >> The line
> >> >> >>      denali->irq_status |= irq_status;
> >> >> >> in denali_isr() accumulates all events that have happened
> >> >> >> since denali_reset_irq().
> >> >> >>
> >> >> >> If the interested IRQs have already happened
> >> >> >> before denali_wait_for_irq(), it just return immediately
> >> >> >> without using completion.
> >> >> >>
> >> >> >> I do not mind adding a comment like below
> >> >> >> if you think my intention is unclear, though.
> >> >> >>
> >> >> >>         /* Return immediately if interested IRQs have already happend. */
> >> >> >>         if (irq_mask & irq_status) {
> >> >> >>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
> >> >> >>                 return irq_status;
> >> >> >>         }
> >> >> >>
> >> >> >>  
> >> >> >
> >> >> > My bad, I didn't notice you were releasing the lock after calling
> >> >> > reinit_completion(). I still find this solution more complex than my
> >> >> > proposal, but I don't care that much.  
> >> >>
> >> >>
> >> >> At first, I implemented exactly like you suggested;
> >> >>    denali->irq_mask = irq_mask;
> >> >>    reinit_completion(&denali->complete)
> >> >> in denali_reset_irq().
> >> >>
> >> >>
> >> >> IIRC, things were like this.
> >> >>
> >> >> Some time later, you memtioned to use ->cmd_ctrl
> >> >> instead of ->cmdfunc.
> >> >>
> >> >> Then I had a problem when I needed to implement
> >> >> denali_check_irq() in
> >> >> http://patchwork.ozlabs.org/patch/772395/
> >> >>
> >> >> denali_wait_for_irq() is blocked until interested IRQ happens.
> >> >> but ->dev_ready() hook should not be blocked.
> >> >> It should return if R/B# transition has happened or not.  
> >> >
> >> > Nope, it should return whether the NAND is ready or not, not whether a
> >> > busy -> ready transition occurred or not. It's typically done by
> >> > reading the NAND STATUS register or by checking the R/B pin status.  
> >>
> >> Checking the R/B pin is probably impossible unless
> >> the pin is changed into a GPIO port.
> >>
> >> I also considered NAND_CMD_STATUS, but
> >> I can not recall why I chose the current approach.
> >> Perhaps I thought returning detected IRQ
> >> is faster than accessing the chip for NAND_CMD_STATUS.
> >>
> >> I can try NAND_CMD_STATUS approach if you like.  
> >
> > Depends what you're trying to do. IIUC, you use denali_wait_for_irq()
> > inside your ->reset()/->read/write_{page,oob}[_raw]() methods, which is
> > perfectly fine (assuming CUSTOM_PAGE_ACCESS is set) since these hooks
> > are expected to wait for chip readiness before returning.
> >
> > You could also implement ->waitfunc() using denali_wait_for_irq() if
> > you're able to detect R/B transitions,  
> 
> R/B transition will set INTR__INT_ACT interrupt.
> 
> I think it is easy in my implementation of denali_wait_for_irq(),
> like
> 
>    denali_wait_for_irq(denali, INTR__INT_ACT);
> 
> 
> 
> But, you are suggesting me to change it.

This is clearly not a hard requirement, I was just curious and wanted
to understand why you had such a convoluted interrupt handling design. I
think I now understand why (see below).

> In your way, you give IRQ masks to denali_reset_irq(), like
> denali_reset_irq(denali, INTR__ERASE_COMP | INTR__ERASE_FAIL);
> 
> Then, we have no room of IRQ bit in denali_wait_for_irq().
> 
> How will you implement it?

It should be pretty easy: just make sure you reset the INTR__INT_ACT
status flag before sending a command (->cmd_ctrl()), and then unmask the
INTR__INT_ACT in denali_waitfunc() just before calling
denali_wait_for_irqs(). This should guarantee that you don't loose any
events, while keeping the logic rather simple.

> 
> 
> > but I'm not sure it's worth it,
> > because you overload almost all the methods using this hook (the only
> > one remaining is ->onfi_set_features(), and using STATUS polling should
> > not be an issue in this case).
> >
> > Implementing ->dev_ready() is not necessary. When not provided, the
> > core falls back to STATUS polling and you seem to support
> > NAND_CMD_STATUS in denali_cmdfunc(). Note that even if it's not fully
> > reliable in the current driver, you're switching to ->cmd_ctrl() at the
> > end of the series anyway, so we should be good after that.  
> 
> ->dev_ready() is optional, but we may end up with waiting more than needed.  
> 
>         case NAND_CMD_RESET:
>                 if (chip->dev_ready)
>                          break;
>                 udelay(chip->chip_delay);
> 
> 
> chip->chip_delay is probably set large enough, so this is not optimal.

That's true, this udelay should not be needed in your case.
 
> 
> 
> If I add something more, the following two bugs were found by
> denali_dev_ready().
> 
> commit 3158fa0e739615769cc047d2428f30f4c3b6640e
> commit c5d664aa5a4c4b257a54eb35045031630d105f49
> 
> 
> If NAND core is fine, denali_dev_ready() works fine too.
> 
> If not, it is a sign of bug of nand_command(_lp).
> This is contributing to the core improvement.
> 

Had a second look at denali_dev_ready() and it seems to do the right
thing, so let's keep it like that.
 
> 
> >>
> >> IIRC, I was thinking like this:
> >>
> >> One IRQ line may be shared among multiple hardware including Denali.
> >> denali_pci may do this.
> >>
> >> The Denali IRQ handler need to check irq status
> >> because it should return IRQ_HANDLED if the event comes from Denali controller.
> >> Otherwise, the event comes from different hardware, so
> >> Denali IRQ handler should return IRQ_NONE.  
> >
> > Correct.
> >  
> >>
> >> wait_for_completion_timeout() may bail out with timeout error,
> >> then proceed to denali_reset_irq() for the next operation.  
> >
> > Before calling denali_reset_irq() you should re-mask the irqs you
> > unmasked in #1. Actually, calling denali_reset_irq() after
> > wait_for_completion_timeout() is not even needed here because you'll
> > clear pending irqs before launching the next NAND command.
> >  
> >> Afterwards, the event actually may happen, and invoke IRQ handler.  
> >
> > Not if you masked IRQs after wait_for_completion_timeout() returned.  
> 
> 
>         wait_for_completion_timeout(&denali->complete, msecs_to_jiffies(1000));
>                 <<< WHAT IF IRQ EVENT HAPPENS HERE ? >>>
>         iowrite32(0, denali->flash_reg + INTR_EN(denali->flash_bank));

You're right, the write to INTR_EN() should be protected by a
spin_lock_irqsave to prevent concurrency between the irq handler and
the thread executing this function (and we should also take the lock
from the irq handler when doing status & mask). I didn't consider the
SMP case when coding this approach (one CPU can handle the interrupt
while the other one continues executing this function after the
timeout).

> 
> 
> 
> 
> Also, you ignore the return value of wait_for_completion_timeout(),
> then drop my precious error message()
> 
>   dev_err(denali->dev, "timeout while waiting for irq 0x%x\n",
>           denali->irq_mask)

Timeout can be detected by testing the status: if none of the flags we
were waiting for are set this is a timeout. Maybe I forgot to add this
message back though.

> 
> 
> 
> > Here is a patch to show you what I had in mind [1] (it applies on top
> > of this patch). AFAICT, there's no races, no interrupt loss, and you
> > get rid of the ->irq_mask/status/lock fields.
> >
> > [1]http://code.bulix.org/fufia6-145571
> >  
> 
> 
> Problem Scenario A
>  [1] wait_for_completion_timeout() exits with timeout.
>  [2] IRQ happens and denali_isr() is invoked
>  [3] iowrite32(0, denali->flash_reg + INTR_EN(denali->flash_bank));
>  [4] status = ioread32(denali->flash_reg + INTR_STATUS(bank)) &
>               ioread32(denali->flash_reg + INTR_EN(bank));
>       (status is set to 0 because INTR_EN(bank) is now 0)
>  [5] return IRQ_NONE;
>  [6] kernel complains  "irq *: nobody cared"

Okay, this is the part I initially misunderstood. Your goal is to never
ever return IRQ_NONE, while I was accepting to rarely return IRQ_NONE
in the unlikely interrupt-just-after-timeout case. Note that the kernel
irq infrastructure accepts rare occurrences or IRQ_NONE [1].

> 
> 
> 
> Problem Scenario B  (unlikely to happen, though)
>  [1] wait_for_completion_timeout() exits with timeout.
>  [2] IRQ happens and denali_isr() is invoked
>  [3] iowrite32(0, denali->flash_reg + INTR_EN(denali->flash_bank));
>  [4] chip->select_chip(mtd, -1)
>  [5] denali->flash_bank = -1
>  [6] status = ioread32(denali->flash_reg + INTR_STATUS(bank)) &
>               ioread32(denali->flash_reg + INTR_EN(bank));
>        ( access to non-existing INTR_STATUS(-1) )

Wrapping the write INTR_EN() into a
spin_lock_irqsave/unlock_irqrestore() section and doing the same in the
interrupt handler (without irqsave/restore) should solve the problem.

This being said, I'm not asking you to change the code, I just wanted
to understand why you were doing it like that.

Thanks,

Boris

[1]http://elixir.free-electrons.com/linux/latest/source/kernel/irq/spurious.c#L407

Re: [PATCH v5 00/23] mtd: nand: denali: Denali NAND IP patch bomb

[Boris Brezillon]

On Thu, 8 Jun 2017 16:12:49 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> 2017-06-08 15:16 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> > Hi Boris,
> >
> > 2017-06-07 20:52 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:  
> >> This patch series intends to solve various problems.
> >>
> >> [1] The driver just retrieves the OOB area as-is
> >>     whereas the controller uses syndrome page layout.
> >> [2] Many NAND chip specific parameters are hard-coded in the driver.
> >> [3] ONFi devices are not working
> >> [4] It can not read Bad Block Marker
> >>
> >> Outstanding changes are:
> >> - Fix raw/oob callbacks for syndrome page layout
> >> - Implement setup_data_interface() callback
> >> - Fix/implement more commands for ONFi devices
> >> - Allow to skip the driver internal bounce buffer
> >> - Support PIO in case DMA is not supported
> >> - Switch from ->cmdfunc over to ->cmd_ctrl  
> >
> >
> > I am planning v6, but
> > how many can you pick-up from this series?
> >
> > I did not see your comments for 01-05, so are they applicable?
> >
> > Could you add
> > Acked-by: Rob Herring <robh@kernel.org>
> > for 05  (http://patchwork.ozlabs.org/patch/772388/)

Applied patches 1 to 5 (with Rob's ack on patch 5).

> >
> > He had already acked it, but I just missed it.
> >  
> 
> BTW, this series can not apply to Boris's tree
> because of the following commit.
> 
> commit 4a78cc644eed3cf2dae00c3a959910a86c140fd6
> Author: Boris Brezillon <boris.brezillon@free-electrons.com>
> Date:   Fri May 26 17:10:15 2017 +0200
> 
>     mtd: nand: Make sure drivers not supporting SET/GET_FEATURES
> return -ENOTSUPP
>

Note that ->setup_data_interface() prototype changed, so you'll have to
adjust patch 9 too.

Regards,

Boris

Re: [PATCH v5 10/23] mtd: nand: denali: rework interrupt handling

[Masahiro Yamada]

Hi Boris,


2017-06-09 16:58 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> Hi Masahiro,
>
> On Fri, 9 Jun 2017 02:26:34 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> Hi Boris
>>
>> 2017-06-09 0:43 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> > On Thu, 8 Jun 2017 21:58:00 +0900
>> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >
>> >> Hi Boris,
>> >>
>> >> 2017-06-08 20:26 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> >> > On Thu, 8 Jun 2017 19:41:39 +0900
>> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >> >
>> >> >> Hi Boris,
>> >> >>
>> >> >>
>> >> >> 2017-06-08 16:12 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> >> >> > Le Thu, 8 Jun 2017 15:10:18 +0900,
>> >> >> > Masahiro Yamada <yamada.masahiro@socionext.com> a écrit :
>> >> >> >
>> >> >> >> Hi Boris,
>> >> >> >>
>> >> >> >>
>> >> >> >> 2017-06-07 22:57 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> >> >> >> > On Wed,  7 Jun 2017 20:52:19 +0900
>> >> >> >> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >> >> >> >
>> >> >> >> >
>> >> >> >> >> -/*
>> >> >> >> >> - * This is the interrupt service routine. It handles all interrupts
>> >> >> >> >> - * sent to this device. Note that on CE4100, this is a shared interrupt.
>> >> >> >> >> - */
>> >> >> >> >> -static irqreturn_t denali_isr(int irq, void *dev_id)
>> >> >> >> >> +static uint32_t denali_wait_for_irq(struct denali_nand_info *denali,
>> >> >> >> >> +                                 uint32_t irq_mask)
>> >> >> >> >>  {
>> >> >> >> >> -     struct denali_nand_info *denali = dev_id;
>> >> >> >> >> +     unsigned long time_left, flags;
>> >> >> >> >>       uint32_t irq_status;
>> >> >> >> >> -     irqreturn_t result = IRQ_NONE;
>> >> >> >> >>
>> >> >> >> >> -     spin_lock(&denali->irq_lock);
>> >> >> >> >> +     spin_lock_irqsave(&denali->irq_lock, flags);
>> >> >> >> >>
>> >> >> >> >> -     /* check to see if a valid NAND chip has been selected. */
>> >> >> >> >> -     if (is_flash_bank_valid(denali->flash_bank)) {
>> >> >> >> >> -             /*
>> >> >> >> >> -              * check to see if controller generated the interrupt,
>> >> >> >> >> -              * since this is a shared interrupt
>> >> >> >> >> -              */
>> >> >> >> >> -             irq_status = denali_irq_detected(denali);
>> >> >> >> >> -             if (irq_status != 0) {
>> >> >> >> >> -                     /* handle interrupt */
>> >> >> >> >> -                     /* first acknowledge it */
>> >> >> >> >> -                     clear_interrupt(denali, irq_status);
>> >> >> >> >> -                     /*
>> >> >> >> >> -                      * store the status in the device context for someone
>> >> >> >> >> -                      * to read
>> >> >> >> >> -                      */
>> >> >> >> >> -                     denali->irq_status |= irq_status;
>> >> >> >> >> -                     /* notify anyone who cares that it happened */
>> >> >> >> >> -                     complete(&denali->complete);
>> >> >> >> >> -                     /* tell the OS that we've handled this */
>> >> >> >> >> -                     result = IRQ_HANDLED;
>> >> >> >> >> -             }
>> >> >> >> >> +     irq_status = denali->irq_status;
>> >> >> >> >> +
>> >> >> >> >> +     if (irq_mask & irq_status) {
>> >> >> >> >> +             spin_unlock_irqrestore(&denali->irq_lock, flags);
>> >> >> >> >> +             return irq_status;
>> >> >> >> >>       }
>> >> >> >> >> -     spin_unlock(&denali->irq_lock);
>> >> >> >> >> -     return result;
>> >> >> >> >> +
>> >> >> >> >> +     denali->irq_mask = irq_mask;
>> >> >> >> >> +     reinit_completion(&denali->complete);
>> >> >> >> >
>> >> >> >> > These 2 instructions should be done before calling
>> >> >> >> > denali_wait_for_irq() (for example in denali_reset_irq()), otherwise
>> >> >> >> > you might loose events if they happen between your irq_status read and
>> >> >> >> > the reinit_completion() call.
>> >> >> >>
>> >> >> >> No.
>> >> >> >>
>> >> >> >> denali->irq_lock avoids a race between denali_isr() and
>> >> >> >> denali_wait_for_irq().
>> >> >> >>
>> >> >> >>
>> >> >> >> The line
>> >> >> >>      denali->irq_status |= irq_status;
>> >> >> >> in denali_isr() accumulates all events that have happened
>> >> >> >> since denali_reset_irq().
>> >> >> >>
>> >> >> >> If the interested IRQs have already happened
>> >> >> >> before denali_wait_for_irq(), it just return immediately
>> >> >> >> without using completion.
>> >> >> >>
>> >> >> >> I do not mind adding a comment like below
>> >> >> >> if you think my intention is unclear, though.
>> >> >> >>
>> >> >> >>         /* Return immediately if interested IRQs have already happend. */
>> >> >> >>         if (irq_mask & irq_status) {
>> >> >> >>                 spin_unlock_irqrestore(&denali->irq_lock, flags);
>> >> >> >>                 return irq_status;
>> >> >> >>         }
>> >> >> >>
>> >> >> >>
>> >> >> >
>> >> >> > My bad, I didn't notice you were releasing the lock after calling
>> >> >> > reinit_completion(). I still find this solution more complex than my
>> >> >> > proposal, but I don't care that much.
>> >> >>
>> >> >>
>> >> >> At first, I implemented exactly like you suggested;
>> >> >>    denali->irq_mask = irq_mask;
>> >> >>    reinit_completion(&denali->complete)
>> >> >> in denali_reset_irq().
>> >> >>
>> >> >>
>> >> >> IIRC, things were like this.
>> >> >>
>> >> >> Some time later, you memtioned to use ->cmd_ctrl
>> >> >> instead of ->cmdfunc.
>> >> >>
>> >> >> Then I had a problem when I needed to implement
>> >> >> denali_check_irq() in
>> >> >> http://patchwork.ozlabs.org/patch/772395/
>> >> >>
>> >> >> denali_wait_for_irq() is blocked until interested IRQ happens.
>> >> >> but ->dev_ready() hook should not be blocked.
>> >> >> It should return if R/B# transition has happened or not.
>> >> >
>> >> > Nope, it should return whether the NAND is ready or not, not whether a
>> >> > busy -> ready transition occurred or not. It's typically done by
>> >> > reading the NAND STATUS register or by checking the R/B pin status.
>> >>
>> >> Checking the R/B pin is probably impossible unless
>> >> the pin is changed into a GPIO port.
>> >>
>> >> I also considered NAND_CMD_STATUS, but
>> >> I can not recall why I chose the current approach.
>> >> Perhaps I thought returning detected IRQ
>> >> is faster than accessing the chip for NAND_CMD_STATUS.
>> >>
>> >> I can try NAND_CMD_STATUS approach if you like.
>> >
>> > Depends what you're trying to do. IIUC, you use denali_wait_for_irq()
>> > inside your ->reset()/->read/write_{page,oob}[_raw]() methods, which is
>> > perfectly fine (assuming CUSTOM_PAGE_ACCESS is set) since these hooks
>> > are expected to wait for chip readiness before returning.
>> >
>> > You could also implement ->waitfunc() using denali_wait_for_irq() if
>> > you're able to detect R/B transitions,
>>
>> R/B transition will set INTR__INT_ACT interrupt.
>>
>> I think it is easy in my implementation of denali_wait_for_irq(),
>> like
>>
>>    denali_wait_for_irq(denali, INTR__INT_ACT);
>>
>>
>>
>> But, you are suggesting me to change it.
>
> This is clearly not a hard requirement, I was just curious and wanted
> to understand why you had such a convoluted interrupt handling design. I
> think I now understand why (see below).
>
>> In your way, you give IRQ masks to denali_reset_irq(), like
>> denali_reset_irq(denali, INTR__ERASE_COMP | INTR__ERASE_FAIL);
>>
>> Then, we have no room of IRQ bit in denali_wait_for_irq().
>>
>> How will you implement it?
>
> It should be pretty easy: just make sure you reset the INTR__INT_ACT
> status flag before sending a command (->cmd_ctrl()), and then unmask the
> INTR__INT_ACT in denali_waitfunc() just before calling
> denali_wait_for_irqs(). This should guarantee that you don't loose any
> events, while keeping the logic rather simple.

Right.  This way will be possible.

One compromise I see is that
it sets INTR__INT_ACT (= wait for R/B# IRQ event) for all commands.
Some commands actually trigger R/B# transition, but some do not.

We can make it precise like nand_command_lp(),
but I do not want to write such a switch statement in my driver.
(this must be maintained for possible new command addition in the future)


Anyway, I will send v6 in my current approach.




>>
>>
>>
>> > Here is a patch to show you what I had in mind [1] (it applies on top
>> > of this patch). AFAICT, there's no races, no interrupt loss, and you
>> > get rid of the ->irq_mask/status/lock fields.
>> >
>> > [1]http://code.bulix.org/fufia6-145571
>> >
>>
>>
>> Problem Scenario A
>>  [1] wait_for_completion_timeout() exits with timeout.
>>  [2] IRQ happens and denali_isr() is invoked
>>  [3] iowrite32(0, denali->flash_reg + INTR_EN(denali->flash_bank));
>>  [4] status = ioread32(denali->flash_reg + INTR_STATUS(bank)) &
>>               ioread32(denali->flash_reg + INTR_EN(bank));
>>       (status is set to 0 because INTR_EN(bank) is now 0)
>>  [5] return IRQ_NONE;
>>  [6] kernel complains  "irq *: nobody cared"
>
> Okay, this is the part I initially misunderstood. Your goal is to never
> ever return IRQ_NONE, while I was accepting to rarely return IRQ_NONE
> in the unlikely interrupt-just-after-timeout case. Note that the kernel
> irq infrastructure accepts rare occurrences or IRQ_NONE [1].

I wanted to be strict here.

But, I did not know the kernel is tolerant with rare IRQ_NONE.
Thanks for the pointer!




-- 
Best Regards
Masahiro Yamada

Re: [PATCH v5 19/23] mtd: nand: denali: fix raw and oob accessors for syndrome page layout

[Masahiro Yamada]

2017-06-08 20:22 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> 2017-06-07 23:09 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> On Wed,  7 Jun 2017 20:52:28 +0900
>> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>>
>>>
>>> +static void denali_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
>>> +{
>>> +     struct denali_nand_info *denali = mtd_to_denali(mtd);
>>> +     int i;
>>> +
>>> +     iowrite32(MODE_11 | BANK(denali->flash_bank) | 2, denali->flash_mem);
>>
>> What is this '| 2'? You seem to use it a lot. Can you define a macro
>> and maybe add a comment if the macro name is not self-descriptive.
>
> The type of access.
>
> bit[1:0] == 0   : command cycle
>             1   : address cycle
>             2   : data read/write cycle
>
> I will replace magic numbers
> with macros or something.


I will add this magic-number/macro consolidation
at the tail of v6.



-- 
Best Regards
Masahiro Yamada