* [PATCH V2, 1/2] mtd: nand: brcmnand: Change brcmnand_set_wp() prototype
@ 2017-02-16 18:46 Kamal Dasu
2017-02-16 18:46 ` [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program Kamal Dasu
0 siblings, 1 reply; 6+ messages in thread
From: Kamal Dasu @ 2017-02-16 18:46 UTC (permalink / raw)
To: linux-mtd
Cc: f.fainelli, bcm-kernel-feedback-list, dwmw2, computersforpeace,
boris.brezillon, marek.vasut, richard, cyrille.pitchen,
Kamal Dasu
Changing brcmnand_set_wp() prototype in prepration for refactoring the nand
write protect logic to add flash status byte check for the protection bit.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
drivers/mtd/nand/brcmnand/brcmnand.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index 42ebd73..c7c4efe 100644
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -765,11 +765,14 @@ enum {
CS_SELECT_AUTO_DEVICE_ID_CFG = BIT(30),
};
-static inline void brcmnand_set_wp(struct brcmnand_controller *ctrl, bool en)
+static int brcmnand_set_wp(struct brcmnand_host *host, int en)
{
+ struct brcmnand_controller *ctrl = host->ctrl;
u32 val = en ? CS_SELECT_NAND_WP : 0;
brcmnand_rmw_reg(ctrl, BRCMNAND_CS_SELECT, CS_SELECT_NAND_WP, 0, val);
+
+ return 0;
}
/***********************************************************************
@@ -1029,7 +1032,7 @@ static void brcmnand_wp(struct mtd_info *mtd, int wp)
dev_dbg(ctrl->dev, "WP %s\n", wp ? "on" : "off");
old_wp = wp;
}
- brcmnand_set_wp(ctrl, wp);
+ brcmnand_set_wp(host, wp);
}
}
@@ -2462,14 +2465,6 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
/* Disable XOR addressing */
brcmnand_rmw_reg(ctrl, BRCMNAND_CS_XOR, 0xff, 0, 0);
- if (ctrl->features & BRCMNAND_HAS_WP) {
- /* Permanently disable write protection */
- if (wp_on == 2)
- brcmnand_set_wp(ctrl, false);
- } else {
- wp_on = 0;
- }
-
/* IRQ */
ctrl->irq = platform_get_irq(pdev, 0);
if ((int)ctrl->irq < 0) {
@@ -2522,6 +2517,18 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
}
list_add_tail(&host->node, &ctrl->host_list);
+
+ if (ctrl->features & BRCMNAND_HAS_WP) {
+ /* Permanently disable write protection */
+ if (wp_on == 2) {
+ ret = brcmnand_set_wp(host, false);
+ if (ret)
+ goto err;
+ }
+ } else {
+ wp_on = 0;
+ }
+
}
}
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program
2017-02-16 18:46 [PATCH V2, 1/2] mtd: nand: brcmnand: Change brcmnand_set_wp() prototype Kamal Dasu
@ 2017-02-16 18:46 ` Kamal Dasu
2017-02-17 21:38 ` Marek Vasut
2017-02-18 8:01 ` [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/programAAs Boris Brezillon
0 siblings, 2 replies; 6+ messages in thread
From: Kamal Dasu @ 2017-02-16 18:46 UTC (permalink / raw)
To: linux-mtd
Cc: f.fainelli, bcm-kernel-feedback-list, dwmw2, computersforpeace,
boris.brezillon, marek.vasut, richard, cyrille.pitchen,
Kamal Dasu
brcmnand controller v6.x and v7.x lets driver to enable disable #WP pin
via NAND_WP bit in CS_SELECT register. Driver implementation assumes that
setting/resetting the bit would assert/de-assert #WP pin instantaneously
from the flash part's perspective, and was proceeding to erase/program
without verifying flash status byte for protection bit. In rigorous
testing this was causing rare data corruptions with erase and/or
subsequent programming. To fix this added verification logic to
brcmandn_wp_set() by reading flash status and verifying protection bit
indicating #WP pin status. The new logic makes sure controller as well
as the flash is ready to accept commands.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
---
drivers/mtd/nand/brcmnand/brcmnand.c | 53 ++++++++++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index c7c4efe..2f082a3 100644
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -101,6 +101,9 @@ struct brcm_nand_dma_desc {
#define BRCMNAND_MIN_BLOCKSIZE (8 * 1024)
#define BRCMNAND_MIN_DEVSIZE (4ULL * 1024 * 1024)
+#define FLASH_RDY (NAND_STATUS_READY)
+#define NAND_CTRL_RDY (INTFC_CTLR_READY | INTFC_FLASH_READY)
+
/* Controller feature flags */
enum {
BRCMNAND_HAS_1K_SECTORS = BIT(0),
@@ -765,12 +768,57 @@ enum {
CS_SELECT_AUTO_DEVICE_ID_CFG = BIT(30),
};
-static int brcmnand_set_wp(struct brcmnand_host *host, int en)
+static void bcmnand_ctrl_busy_poll(struct brcmnand_controller *ctrl, u32 mask)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(200);
+
+ while ((brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) & mask) !=
+ mask) {
+ if (time_after(jiffies, timeout)) {
+ dev_warn(ctrl->dev, "timeout on ctrl_ready\n");
+ break;
+ }
+ cpu_relax();
+ }
+}
+
+static inline void brcmnand_set_wp_reg(struct brcmnand_controller *ctrl, int en)
{
- struct brcmnand_controller *ctrl = host->ctrl;
u32 val = en ? CS_SELECT_NAND_WP : 0;
brcmnand_rmw_reg(ctrl, BRCMNAND_CS_SELECT, CS_SELECT_NAND_WP, 0, val);
+}
+
+static int brcmnand_set_wp(struct brcmnand_host *host, int en)
+{
+ struct brcmnand_controller *ctrl = host->ctrl;
+ struct mtd_info *mtd = nand_to_mtd(&host->chip);
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ u32 sts_reg;
+ bool is_wp;
+
+ /*
+ * make sure ctrl/flash ready before and after
+ * changing state of WP PIN
+ */
+ bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
+ brcmnand_set_wp_reg(ctrl, en);
+ chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+ bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
+ sts_reg = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
+ /* NAND_STATUS_WP 0x80 = not protected, 0x00 = protected */
+ is_wp = (sts_reg & NAND_STATUS_WP) ? false : true;
+
+ if (is_wp != en) {
+ u32 nand_wp = brcmnand_read_reg(ctrl, BRCMNAND_CS_SELECT);
+
+ nand_wp &= CS_SELECT_NAND_WP;
+ dev_err_ratelimited(&host->pdev->dev,
+ "#WP %s sts:0x%x expected %s NAND_WP 0x%x\n",
+ is_wp ? "On" : "Off", sts_reg & 0xff,
+ en ? "On" : "Off", nand_wp ? 1 : 0);
+ return -EINVAL;
+ }
return 0;
}
@@ -1167,6 +1215,7 @@ static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)
BUG_ON(ctrl->cmd_pending != 0);
ctrl->cmd_pending = cmd;
+ bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY);
intfc = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
WARN_ON(!(intfc & INTFC_CTLR_READY));
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program
2017-02-16 18:46 ` [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program Kamal Dasu
@ 2017-02-17 21:38 ` Marek Vasut
2017-02-18 8:03 ` Boris Brezillon
2017-02-18 8:01 ` [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/programAAs Boris Brezillon
1 sibling, 1 reply; 6+ messages in thread
From: Marek Vasut @ 2017-02-17 21:38 UTC (permalink / raw)
To: Kamal Dasu, linux-mtd
Cc: f.fainelli, bcm-kernel-feedback-list, dwmw2, computersforpeace,
boris.brezillon, richard, cyrille.pitchen
On 02/16/2017 07:46 PM, Kamal Dasu wrote:
> brcmnand controller v6.x and v7.x lets driver to enable disable #WP pin
> via NAND_WP bit in CS_SELECT register. Driver implementation assumes that
> setting/resetting the bit would assert/de-assert #WP pin instantaneously
> from the flash part's perspective, and was proceeding to erase/program
> without verifying flash status byte for protection bit. In rigorous
> testing this was causing rare data corruptions with erase and/or
> subsequent programming. To fix this added verification logic to
> brcmandn_wp_set() by reading flash status and verifying protection bit
> indicating #WP pin status. The new logic makes sure controller as well
> as the flash is ready to accept commands.
>
> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> ---
> drivers/mtd/nand/brcmnand/brcmnand.c | 53 ++++++++++++++++++++++++++++++++++--
> 1 file changed, 51 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
> index c7c4efe..2f082a3 100644
> --- a/drivers/mtd/nand/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/brcmnand/brcmnand.c
> @@ -101,6 +101,9 @@ struct brcm_nand_dma_desc {
> #define BRCMNAND_MIN_BLOCKSIZE (8 * 1024)
> #define BRCMNAND_MIN_DEVSIZE (4ULL * 1024 * 1024)
>
> +#define FLASH_RDY (NAND_STATUS_READY)
Drop extra parenthesis
> +#define NAND_CTRL_RDY (INTFC_CTLR_READY | INTFC_FLASH_READY)
> +
> /* Controller feature flags */
> enum {
> BRCMNAND_HAS_1K_SECTORS = BIT(0),
> @@ -765,12 +768,57 @@ enum {
> CS_SELECT_AUTO_DEVICE_ID_CFG = BIT(30),
> };
>
> -static int brcmnand_set_wp(struct brcmnand_host *host, int en)
> +static void bcmnand_ctrl_busy_poll(struct brcmnand_controller *ctrl, u32 mask)
> +{
> + unsigned long timeout = jiffies + msecs_to_jiffies(200);
> +
> + while ((brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) & mask) !=
> + mask) {
Ewww, make this into something like ...
while (true) { / for (;;) {
reg = read.....
if ((reg & mask) == mask)
...
if (time ....)
dev_warn...
cpu_relax();
}
But then again, there's the readx_poll_timeout() , which seems like
exactly the thing you implemented here .
> + if (time_after(jiffies, timeout)) {
> + dev_warn(ctrl->dev, "timeout on ctrl_ready\n");
> + break;
> + }
> + cpu_relax();
> + }
> +}
> +
> +static inline void brcmnand_set_wp_reg(struct brcmnand_controller *ctrl, int en)
> {
> - struct brcmnand_controller *ctrl = host->ctrl;
> u32 val = en ? CS_SELECT_NAND_WP : 0;
>
> brcmnand_rmw_reg(ctrl, BRCMNAND_CS_SELECT, CS_SELECT_NAND_WP, 0, val);
> +}
> +
> +static int brcmnand_set_wp(struct brcmnand_host *host, int en)
> +{
> + struct brcmnand_controller *ctrl = host->ctrl;
> + struct mtd_info *mtd = nand_to_mtd(&host->chip);
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + u32 sts_reg;
> + bool is_wp;
> +
> + /*
> + * make sure ctrl/flash ready before and after
> + * changing state of WP PIN
> + */
> + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
> + brcmnand_set_wp_reg(ctrl, en);
> + chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
> + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
> + sts_reg = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
> + /* NAND_STATUS_WP 0x80 = not protected, 0x00 = protected */
> + is_wp = (sts_reg & NAND_STATUS_WP) ? false : true;
I dont think you need the ternary op here.
> + if (is_wp != en) {
> + u32 nand_wp = brcmnand_read_reg(ctrl, BRCMNAND_CS_SELECT);
> +
> + nand_wp &= CS_SELECT_NAND_WP;
> + dev_err_ratelimited(&host->pdev->dev,
> + "#WP %s sts:0x%x expected %s NAND_WP 0x%x\n",
> + is_wp ? "On" : "Off", sts_reg & 0xff,
> + en ? "On" : "Off", nand_wp ? 1 : 0);
> + return -EINVAL;
> + }
>
> return 0;
> }
> @@ -1167,6 +1215,7 @@ static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)
> BUG_ON(ctrl->cmd_pending != 0);
> ctrl->cmd_pending = cmd;
>
> + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY);
> intfc = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
> WARN_ON(!(intfc & INTFC_CTLR_READY));
>
>
--
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/programAAs
2017-02-16 18:46 ` [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program Kamal Dasu
2017-02-17 21:38 ` Marek Vasut
@ 2017-02-18 8:01 ` Boris Brezillon
1 sibling, 0 replies; 6+ messages in thread
From: Boris Brezillon @ 2017-02-18 8:01 UTC (permalink / raw)
To: Kamal Dasu
Cc: linux-mtd, f.fainelli, richard, marek.vasut,
bcm-kernel-feedback-list, cyrille.pitchen, computersforpeace,
dwmw2
On Thu, 16 Feb 2017 13:46:52 -0500
Kamal Dasu <kdasu.kdev@gmail.com> wrote:
> brcmnand controller v6.x and v7.x lets driver to enable disable #WP pin
> via NAND_WP bit in CS_SELECT register. Driver implementation assumes that
> setting/resetting the bit would assert/de-assert #WP pin instantaneously
> from the flash part's perspective, and was proceeding to erase/program
> without verifying flash status byte for protection bit. In rigorous
> testing this was causing rare data corruptions with erase and/or
> subsequent programming. To fix this added verification logic to
> brcmandn_wp_set() by reading flash status and verifying protection bit
> indicating #WP pin status. The new logic makes sure controller as well
> as the flash is ready to accept commands.
>
> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> ---
> drivers/mtd/nand/brcmnand/brcmnand.c | 53 ++++++++++++++++++++++++++++++++++--
> 1 file changed, 51 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
> index c7c4efe..2f082a3 100644
> --- a/drivers/mtd/nand/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/brcmnand/brcmnand.c
> @@ -101,6 +101,9 @@ struct brcm_nand_dma_desc {
> #define BRCMNAND_MIN_BLOCKSIZE (8 * 1024)
> #define BRCMNAND_MIN_DEVSIZE (4ULL * 1024 * 1024)
>
> +#define FLASH_RDY (NAND_STATUS_READY)
Drop FLASH_RDY and use NAND_STATUS_READY directly. This re-definition
just adds more confusion.
> +#define NAND_CTRL_RDY (INTFC_CTLR_READY | INTFC_FLASH_READY)
> +
> /* Controller feature flags */
> enum {
> BRCMNAND_HAS_1K_SECTORS = BIT(0),
> @@ -765,12 +768,57 @@ enum {
> CS_SELECT_AUTO_DEVICE_ID_CFG = BIT(30),
> };
>
> -static int brcmnand_set_wp(struct brcmnand_host *host, int en)
> +static void bcmnand_ctrl_busy_poll(struct brcmnand_controller *ctrl, u32 mask)
> +{
> + unsigned long timeout = jiffies + msecs_to_jiffies(200);
> +
> + while ((brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) & mask) !=
> + mask) {
> + if (time_after(jiffies, timeout)) {
> + dev_warn(ctrl->dev, "timeout on ctrl_ready\n");
> + break;
> + }
> + cpu_relax();
> + }
> +}
> +
> +static inline void brcmnand_set_wp_reg(struct brcmnand_controller *ctrl, int en)
> {
> - struct brcmnand_controller *ctrl = host->ctrl;
> u32 val = en ? CS_SELECT_NAND_WP : 0;
>
> brcmnand_rmw_reg(ctrl, BRCMNAND_CS_SELECT, CS_SELECT_NAND_WP, 0, val);
> +}
> +
> +static int brcmnand_set_wp(struct brcmnand_host *host, int en)
> +{
> + struct brcmnand_controller *ctrl = host->ctrl;
> + struct mtd_info *mtd = nand_to_mtd(&host->chip);
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + u32 sts_reg;
> + bool is_wp;
> +
> + /*
> + * make sure ctrl/flash ready before and after
> + * changing state of WP PIN
> + */
> + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
> + brcmnand_set_wp_reg(ctrl, en);
> + chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
> + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
> + sts_reg = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
> + /* NAND_STATUS_WP 0x80 = not protected, 0x00 = protected */
> + is_wp = (sts_reg & NAND_STATUS_WP) ? false : true;
> +
> + if (is_wp != en) {
> + u32 nand_wp = brcmnand_read_reg(ctrl, BRCMNAND_CS_SELECT);
> +
> + nand_wp &= CS_SELECT_NAND_WP;
> + dev_err_ratelimited(&host->pdev->dev,
> + "#WP %s sts:0x%x expected %s NAND_WP 0x%x\n",
> + is_wp ? "On" : "Off", sts_reg & 0xff,
> + en ? "On" : "Off", nand_wp ? 1 : 0);
> + return -EINVAL;
> + }
>
> return 0;
> }
> @@ -1167,6 +1215,7 @@ static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)
> BUG_ON(ctrl->cmd_pending != 0);
> ctrl->cmd_pending = cmd;
>
> + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY);
> intfc = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
> WARN_ON(!(intfc & INTFC_CTLR_READY));
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program
2017-02-17 21:38 ` Marek Vasut
@ 2017-02-18 8:03 ` Boris Brezillon
2017-02-18 15:21 ` Marek Vasut
0 siblings, 1 reply; 6+ messages in thread
From: Boris Brezillon @ 2017-02-18 8:03 UTC (permalink / raw)
To: Marek Vasut
Cc: Kamal Dasu, linux-mtd, f.fainelli, richard,
bcm-kernel-feedback-list, cyrille.pitchen, computersforpeace,
dwmw2
On Fri, 17 Feb 2017 22:38:04 +0100
Marek Vasut <marek.vasut@gmail.com> wrote:
> On 02/16/2017 07:46 PM, Kamal Dasu wrote:
> > brcmnand controller v6.x and v7.x lets driver to enable disable #WP pin
> > via NAND_WP bit in CS_SELECT register. Driver implementation assumes that
> > setting/resetting the bit would assert/de-assert #WP pin instantaneously
> > from the flash part's perspective, and was proceeding to erase/program
> > without verifying flash status byte for protection bit. In rigorous
> > testing this was causing rare data corruptions with erase and/or
> > subsequent programming. To fix this added verification logic to
> > brcmandn_wp_set() by reading flash status and verifying protection bit
> > indicating #WP pin status. The new logic makes sure controller as well
> > as the flash is ready to accept commands.
> >
> > Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
> > ---
> > drivers/mtd/nand/brcmnand/brcmnand.c | 53 ++++++++++++++++++++++++++++++++++--
> > 1 file changed, 51 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
> > index c7c4efe..2f082a3 100644
> > --- a/drivers/mtd/nand/brcmnand/brcmnand.c
> > +++ b/drivers/mtd/nand/brcmnand/brcmnand.c
> > @@ -101,6 +101,9 @@ struct brcm_nand_dma_desc {
> > #define BRCMNAND_MIN_BLOCKSIZE (8 * 1024)
> > #define BRCMNAND_MIN_DEVSIZE (4ULL * 1024 * 1024)
> >
> > +#define FLASH_RDY (NAND_STATUS_READY)
>
> Drop extra parenthesis
>
> > +#define NAND_CTRL_RDY (INTFC_CTLR_READY | INTFC_FLASH_READY)
> > +
> > /* Controller feature flags */
> > enum {
> > BRCMNAND_HAS_1K_SECTORS = BIT(0),
> > @@ -765,12 +768,57 @@ enum {
> > CS_SELECT_AUTO_DEVICE_ID_CFG = BIT(30),
> > };
> >
> > -static int brcmnand_set_wp(struct brcmnand_host *host, int en)
> > +static void bcmnand_ctrl_busy_poll(struct brcmnand_controller *ctrl, u32 mask)
> > +{
> > + unsigned long timeout = jiffies + msecs_to_jiffies(200);
> > +
> > + while ((brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) & mask) !=
> > + mask) {
>
> Ewww, make this into something like ...
>
> while (true) { / for (;;) {
> reg = read.....
> if ((reg & mask) == mask)
> ...
> if (time ....)
> dev_warn...
> cpu_relax();
> }
>
> But then again, there's the readx_poll_timeout() , which seems like
> exactly the thing you implemented here .
I agree that using readl_poll_timeout() would be better, but it's not
so simple (see brcmnand_read_reg() and brcmnand_readl()
implementations).
>
> > + if (time_after(jiffies, timeout)) {
> > + dev_warn(ctrl->dev, "timeout on ctrl_ready\n");
> > + break;
> > + }
> > + cpu_relax();
> > + }
> > +}
> > +
> > +static inline void brcmnand_set_wp_reg(struct brcmnand_controller *ctrl, int en)
> > {
> > - struct brcmnand_controller *ctrl = host->ctrl;
> > u32 val = en ? CS_SELECT_NAND_WP : 0;
> >
> > brcmnand_rmw_reg(ctrl, BRCMNAND_CS_SELECT, CS_SELECT_NAND_WP, 0, val);
> > +}
> > +
> > +static int brcmnand_set_wp(struct brcmnand_host *host, int en)
> > +{
> > + struct brcmnand_controller *ctrl = host->ctrl;
> > + struct mtd_info *mtd = nand_to_mtd(&host->chip);
> > + struct nand_chip *chip = mtd_to_nand(mtd);
> > + u32 sts_reg;
> > + bool is_wp;
> > +
> > + /*
> > + * make sure ctrl/flash ready before and after
> > + * changing state of WP PIN
> > + */
> > + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
> > + brcmnand_set_wp_reg(ctrl, en);
> > + chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
> > + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY | FLASH_RDY);
> > + sts_reg = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
> > + /* NAND_STATUS_WP 0x80 = not protected, 0x00 = protected */
> > + is_wp = (sts_reg & NAND_STATUS_WP) ? false : true;
>
> I dont think you need the ternary op here.
Indeed.
>
> > + if (is_wp != en) {
> > + u32 nand_wp = brcmnand_read_reg(ctrl, BRCMNAND_CS_SELECT);
> > +
> > + nand_wp &= CS_SELECT_NAND_WP;
> > + dev_err_ratelimited(&host->pdev->dev,
> > + "#WP %s sts:0x%x expected %s NAND_WP 0x%x\n",
> > + is_wp ? "On" : "Off", sts_reg & 0xff,
> > + en ? "On" : "Off", nand_wp ? 1 : 0);
> > + return -EINVAL;
> > + }
> >
> > return 0;
> > }
> > @@ -1167,6 +1215,7 @@ static void brcmnand_send_cmd(struct brcmnand_host *host, int cmd)
> > BUG_ON(ctrl->cmd_pending != 0);
> > ctrl->cmd_pending = cmd;
> >
> > + bcmnand_ctrl_busy_poll(ctrl, NAND_CTRL_RDY);
> > intfc = brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS);
> > WARN_ON(!(intfc & INTFC_CTLR_READY));
> >
> >
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program
2017-02-18 8:03 ` Boris Brezillon
@ 2017-02-18 15:21 ` Marek Vasut
0 siblings, 0 replies; 6+ messages in thread
From: Marek Vasut @ 2017-02-18 15:21 UTC (permalink / raw)
To: Boris Brezillon
Cc: Kamal Dasu, linux-mtd, f.fainelli, richard,
bcm-kernel-feedback-list, cyrille.pitchen, computersforpeace,
dwmw2
On 02/18/2017 09:03 AM, Boris Brezillon wrote:
> On Fri, 17 Feb 2017 22:38:04 +0100
> Marek Vasut <marek.vasut@gmail.com> wrote:
>
>> On 02/16/2017 07:46 PM, Kamal Dasu wrote:
>>> brcmnand controller v6.x and v7.x lets driver to enable disable #WP pin
>>> via NAND_WP bit in CS_SELECT register. Driver implementation assumes that
>>> setting/resetting the bit would assert/de-assert #WP pin instantaneously
>>> from the flash part's perspective, and was proceeding to erase/program
>>> without verifying flash status byte for protection bit. In rigorous
>>> testing this was causing rare data corruptions with erase and/or
>>> subsequent programming. To fix this added verification logic to
>>> brcmandn_wp_set() by reading flash status and verifying protection bit
>>> indicating #WP pin status. The new logic makes sure controller as well
>>> as the flash is ready to accept commands.
>>>
>>> Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
>>> ---
>>> drivers/mtd/nand/brcmnand/brcmnand.c | 53 ++++++++++++++++++++++++++++++++++--
>>> 1 file changed, 51 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
>>> index c7c4efe..2f082a3 100644
>>> --- a/drivers/mtd/nand/brcmnand/brcmnand.c
>>> +++ b/drivers/mtd/nand/brcmnand/brcmnand.c
>>> @@ -101,6 +101,9 @@ struct brcm_nand_dma_desc {
>>> #define BRCMNAND_MIN_BLOCKSIZE (8 * 1024)
>>> #define BRCMNAND_MIN_DEVSIZE (4ULL * 1024 * 1024)
>>>
>>> +#define FLASH_RDY (NAND_STATUS_READY)
>>
>> Drop extra parenthesis
>>
>>> +#define NAND_CTRL_RDY (INTFC_CTLR_READY | INTFC_FLASH_READY)
>>> +
>>> /* Controller feature flags */
>>> enum {
>>> BRCMNAND_HAS_1K_SECTORS = BIT(0),
>>> @@ -765,12 +768,57 @@ enum {
>>> CS_SELECT_AUTO_DEVICE_ID_CFG = BIT(30),
>>> };
>>>
>>> -static int brcmnand_set_wp(struct brcmnand_host *host, int en)
>>> +static void bcmnand_ctrl_busy_poll(struct brcmnand_controller *ctrl, u32 mask)
>>> +{
>>> + unsigned long timeout = jiffies + msecs_to_jiffies(200);
>>> +
>>> + while ((brcmnand_read_reg(ctrl, BRCMNAND_INTFC_STATUS) & mask) !=
>>> + mask) {
>>
>> Ewww, make this into something like ...
>>
>> while (true) { / for (;;) {
>> reg = read.....
>> if ((reg & mask) == mask)
>> ...
>> if (time ....)
>> dev_warn...
>> cpu_relax();
>> }
>>
>> But then again, there's the readx_poll_timeout() , which seems like
>> exactly the thing you implemented here .
>
> I agree that using readl_poll_timeout() would be better, but it's not
> so simple (see brcmnand_read_reg() and brcmnand_readl()
> implementations).
I admit I didn't look at how those are implemented.
--
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-02-18 15:22 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-16 18:46 [PATCH V2, 1/2] mtd: nand: brcmnand: Change brcmnand_set_wp() prototype Kamal Dasu
2017-02-16 18:46 ` [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/program Kamal Dasu
2017-02-17 21:38 ` Marek Vasut
2017-02-18 8:03 ` Boris Brezillon
2017-02-18 15:21 ` Marek Vasut
2017-02-18 8:01 ` [PATCH V2, 2/2] mtd: nand: brcmnand: Check flash #WP pin status before nand erase/programAAs Boris Brezillon
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