[PATCH v4 1/5] i2c: designware: Rename accessor_flags to flags

[PATCH v4 1/5] i2c: designware: Rename accessor_flags to flags

[Hans de Goede]

Rename accessor_flags to flags, so that we can use the field for
other flags too. This is a preparation patch for adding cherrytrail
support to the punit semaphore code.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/i2c/busses/i2c-designware-core.c    | 14 +++++++-------
 drivers/i2c/busses/i2c-designware-core.h    |  2 +-
 drivers/i2c/busses/i2c-designware-platdrv.c |  2 +-
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index b403fa5..b6a7989 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -177,13 +177,13 @@ static u32 dw_readl(struct dw_i2c_dev *dev, int offset)
 {
 	u32 value;
 
-	if (dev->accessor_flags & ACCESS_16BIT)
+	if (dev->flags & ACCESS_16BIT)
 		value = readw_relaxed(dev->base + offset) |
 			(readw_relaxed(dev->base + offset + 2) << 16);
 	else
 		value = readl_relaxed(dev->base + offset);
 
-	if (dev->accessor_flags & ACCESS_SWAP)
+	if (dev->flags & ACCESS_SWAP)
 		return swab32(value);
 	else
 		return value;
@@ -191,10 +191,10 @@ static u32 dw_readl(struct dw_i2c_dev *dev, int offset)
 
 static void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
 {
-	if (dev->accessor_flags & ACCESS_SWAP)
+	if (dev->flags & ACCESS_SWAP)
 		b = swab32(b);
 
-	if (dev->accessor_flags & ACCESS_16BIT) {
+	if (dev->flags & ACCESS_16BIT) {
 		writew_relaxed((u16)b, dev->base + offset);
 		writew_relaxed((u16)(b >> 16), dev->base + offset + 2);
 	} else {
@@ -339,10 +339,10 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 	reg = dw_readl(dev, DW_IC_COMP_TYPE);
 	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
 		/* Configure register endianess access */
-		dev->accessor_flags |= ACCESS_SWAP;
+		dev->flags |= ACCESS_SWAP;
 	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
 		/* Configure register access mode 16bit */
-		dev->accessor_flags |= ACCESS_16BIT;
+		dev->flags |= ACCESS_16BIT;
 	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
 		dev_err(dev->dev, "Unknown Synopsys component type: "
 			"0x%08x\n", reg);
@@ -886,7 +886,7 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
 tx_aborted:
 	if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
 		complete(&dev->cmd_complete);
-	else if (unlikely(dev->accessor_flags & ACCESS_INTR_MASK)) {
+	else if (unlikely(dev->flags & ACCESS_INTR_MASK)) {
 		/* workaround to trigger pending interrupt */
 		stat = dw_readl(dev, DW_IC_INTR_MASK);
 		i2c_dw_disable_int(dev);
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 0d44d2a..fb143f5 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -95,7 +95,7 @@ struct dw_i2c_dev {
 	unsigned int		status;
 	u32			abort_source;
 	int			irq;
-	u32			accessor_flags;
+	u32			flags;
 	struct i2c_adapter	adapter;
 	u32			functionality;
 	u32			master_cfg;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0b42a12..97a2ca1 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -112,7 +112,7 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev)
 
 	id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
 	if (id && id->driver_data)
-		dev->accessor_flags |= (u32)id->driver_data;
+		dev->flags |= (u32)id->driver_data;
 
 	return 0;
 }
-- 
2.9.3

[PATCH v4 2/5] i2c: designware-baytrail: Pass dw_i2c_dev into helper functions

[Hans de Goede]

Pass dw_i2c_dev into the helper functions, this is a preparation patch
for the punit semaphore fixes done in the other patches in this set.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 1590ad0..a3f581c 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -28,14 +28,14 @@
 
 static unsigned long acquired;
 
-static int get_sem(struct device *dev, u32 *sem)
+static int get_sem(struct dw_i2c_dev *dev, u32 *sem)
 {
 	u32 data;
 	int ret;
 
 	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data);
 	if (ret) {
-		dev_err(dev, "iosf failed to read punit semaphore\n");
+		dev_err(dev->dev, "iosf failed to read punit semaphore\n");
 		return ret;
 	}
 
@@ -44,18 +44,18 @@ static int get_sem(struct device *dev, u32 *sem)
 	return 0;
 }
 
-static void reset_semaphore(struct device *dev)
+static void reset_semaphore(struct dw_i2c_dev *dev)
 {
 	u32 data;
 
 	if (iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data)) {
-		dev_err(dev, "iosf failed to reset punit semaphore during read\n");
+		dev_err(dev->dev, "iosf failed to reset punit semaphore during read\n");
 		return;
 	}
 
 	data &= ~PUNIT_SEMAPHORE_BIT;
 	if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, data))
-		dev_err(dev, "iosf failed to reset punit semaphore during write\n");
+		dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n");
 }
 
 static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
@@ -83,7 +83,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	start = jiffies;
 	end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT);
 	do {
-		ret = get_sem(dev->dev, &sem);
+		ret = get_sem(dev, &sem);
 		if (!ret && sem) {
 			acquired = jiffies;
 			dev_dbg(dev->dev, "punit semaphore acquired after %ums\n",
@@ -95,7 +95,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	} while (time_before(jiffies, end));
 
 	dev_err(dev->dev, "punit semaphore timed out, resetting\n");
-	reset_semaphore(dev->dev);
+	reset_semaphore(dev);
 
 	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &sem);
 	if (ret)
@@ -116,7 +116,7 @@ static void baytrail_i2c_release(struct dw_i2c_dev *dev)
 	if (!dev->acquire_lock)
 		return;
 
-	reset_semaphore(dev->dev);
+	reset_semaphore(dev);
 	dev_dbg(dev->dev, "punit semaphore held for %ums\n",
 		jiffies_to_msecs(jiffies - acquired));
 }
-- 
2.9.3

[PATCH v4 3/5] i2c: designware-baytrail: Only check iosf_mbi_available() for shared hosts

[Hans de Goede]

If (!shared_host) simply return 0, this avoids delaying the probe if
iosf_mbi_available() returns false when an i2c bus is not using the
punit semaphore.

Also move the if (!iosf_mbi_available()) check to above the
dev_info, so that we do not repeat the dev_info on every probe
until iosf_mbi_available() returns true.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
---
Changes in v2:
-New patch in v2 of this set
Changes in v3:
-Use if (!shared_host) return 0, to simplify the non-shared_host path
 and to avoid nested ifs
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index a3f581c..cf02222 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -138,15 +138,16 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
 	if (ACPI_FAILURE(status))
 		return 0;
 
-	if (shared_host) {
-		dev_info(dev->dev, "I2C bus managed by PUNIT\n");
-		dev->acquire_lock = baytrail_i2c_acquire;
-		dev->release_lock = baytrail_i2c_release;
-		dev->pm_runtime_disabled = true;
-	}
+	if (!shared_host)
+		return 0;
 
 	if (!iosf_mbi_available())
 		return -EPROBE_DEFER;
 
+	dev_info(dev->dev, "I2C bus managed by PUNIT\n");
+	dev->acquire_lock = baytrail_i2c_acquire;
+	dev->release_lock = baytrail_i2c_release;
+	dev->pm_runtime_disabled = true;
+
 	return 0;
 }
-- 
2.9.3

[PATCH v4 4/5] i2c: designware-baytrail: Disallow the CPU to enter C6 or C7 while holding the punit semaphore

[Hans de Goede]

On my cherrytrail tablet with axp288 pmic, just doing a bunch of repeated
reads from the pmic, e.g. "i2cdump -y 14 0x34" would lookup the tablet in
1 - 3 runs guaranteed.

This seems to be causes by the cpu trying to enter C6 or C7 while we hold
the punit bus semaphore, at which point everything just hangs.

Avoid this by disallowing the CPU to enter C6 or C7 before acquiring the
punit bus semaphore.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109051
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
---
Changes in v2:
-New patch in v2 of this set
Changes in v3:
-Change commit message and comment in the code from "force the CPU to C1"
 to "Disallow the CPU to enter C6 or C7", as the CPU may still be in either
 C0 or C1 with the request pm_qos
Changes in v4:
-Rename i2c_dw_eval_lock_support to i2c_dw_probe_lock_support so that we can
 add a matching i2c_dw_remove_lock_support cleanup function
-Move qm_pos removal to new i2c_dw_remove_lock_support function
-Move pm_qos_add_request to the end of i2c_dw_probe_lock_support
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 21 ++++++++++++++++++++-
 drivers/i2c/busses/i2c-designware-core.h     |  9 +++++++--
 drivers/i2c/busses/i2c-designware-platdrv.c  |  4 +++-
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index cf02222..95d7013 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -16,6 +16,7 @@
 #include <linux/acpi.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/pm_qos.h>
 
 #include <asm/iosf_mbi.h>
 
@@ -33,6 +34,13 @@ static int get_sem(struct dw_i2c_dev *dev, u32 *sem)
 	u32 data;
 	int ret;
 
+	/*
+	 * Disallow the CPU to enter C6 or C7 state, entering these states
+	 * requires the punit to talk to the pmic and if this happens while
+	 * we're holding the semaphore, the SoC hangs.
+	 */
+	pm_qos_update_request(&dev->pm_qos, 0);
+
 	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data);
 	if (ret) {
 		dev_err(dev->dev, "iosf failed to read punit semaphore\n");
@@ -56,6 +64,8 @@ static void reset_semaphore(struct dw_i2c_dev *dev)
 	data &= ~PUNIT_SEMAPHORE_BIT;
 	if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, data))
 		dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n");
+
+	pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);
 }
 
 static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
@@ -121,7 +131,7 @@ static void baytrail_i2c_release(struct dw_i2c_dev *dev)
 		jiffies_to_msecs(jiffies - acquired));
 }
 
-int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
+int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev)
 {
 	acpi_status status;
 	unsigned long long shared_host = 0;
@@ -149,5 +159,14 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
 	dev->release_lock = baytrail_i2c_release;
 	dev->pm_runtime_disabled = true;
 
+	pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY,
+			   PM_QOS_DEFAULT_VALUE);
+
 	return 0;
 }
+
+void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev)
+{
+	if (dev->acquire_lock)
+		pm_qos_remove_request(&dev->pm_qos);
+}
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index fb143f5..871970e 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -22,6 +22,7 @@
  *
  */
 
+#include <linux/pm_qos.h>
 
 #define DW_IC_CON_MASTER		0x1
 #define DW_IC_CON_SPEED_STD		0x2
@@ -67,6 +68,7 @@
  * @fp_lcnt: fast plus LCNT value
  * @hs_hcnt: high speed HCNT value
  * @hs_lcnt: high speed LCNT value
+ * @pm_qos: pm_qos_request used while holding a hardware lock on the bus
  * @acquire_lock: function to acquire a hardware lock on the bus
  * @release_lock: function to release a hardware lock on the bus
  * @pm_runtime_disabled: true if pm runtime is disabled
@@ -114,6 +116,7 @@ struct dw_i2c_dev {
 	u16			fp_lcnt;
 	u16			hs_hcnt;
 	u16			hs_lcnt;
+	struct pm_qos_request	pm_qos;
 	int			(*acquire_lock)(struct dw_i2c_dev *dev);
 	void			(*release_lock)(struct dw_i2c_dev *dev);
 	bool			pm_runtime_disabled;
@@ -131,7 +134,9 @@ extern u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev);
 extern int i2c_dw_probe(struct dw_i2c_dev *dev);
 
 #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
-extern int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev);
+extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);
+extern void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev);
 #else
-static inline int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) { return 0; }
+static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { return 0; }
+static inline void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) {}
 #endif
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 97a2ca1..b0a64a2 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -210,7 +210,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	r = i2c_dw_eval_lock_support(dev);
+	r = i2c_dw_probe_lock_support(dev);
 	if (r)
 		return r;
 
@@ -291,6 +291,8 @@ static int dw_i2c_plat_remove(struct platform_device *pdev)
 	if (!dev->pm_runtime_disabled)
 		pm_runtime_disable(&pdev->dev);
 
+	i2c_dw_remove_lock_support(dev);
+
 	return 0;
 }
 
-- 
2.9.3

[PATCH v4 5/5] i2c: designware-baytrail: Add support for cherrytrail

[Hans de Goede]

The cherrytrail punit has the pmic i2c bus access semaphore at a
different register address.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
Changes in v2:
-Adjust for accessor_flags -> flags rename
-Add flags field to struct dw_pci_controller
-Add get_sem_addr() helper replacing MODEL_CHERRYTRAIL flag checking in
 PUNIT_SEMAPHORE macro
Changes in v3:
-Add a gap between ACCESS_* and MODEL_* flags as reserved space for
 future ACCESS_* flags
Changes in v4:
-s/CHV/CHT/
---
 drivers/i2c/busses/i2c-designware-baytrail.c | 22 +++++++++++++++++-----
 drivers/i2c/busses/i2c-designware-core.h     |  2 ++
 drivers/i2c/busses/i2c-designware-pcidrv.c   | 26 +++++++++++++++++++-------
 drivers/i2c/busses/i2c-designware-platdrv.c  |  2 +-
 4 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c
index 95d7013..9481411 100644
--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -24,13 +24,23 @@
 
 #define SEMAPHORE_TIMEOUT	100
 #define PUNIT_SEMAPHORE		0x7
+#define PUNIT_SEMAPHORE_CHT	0x10e
 #define PUNIT_SEMAPHORE_BIT	BIT(0)
 #define PUNIT_SEMAPHORE_ACQUIRE	BIT(1)
 
 static unsigned long acquired;
 
+static u32 get_sem_addr(struct dw_i2c_dev *dev)
+{
+	if (dev->flags & MODEL_CHERRYTRAIL)
+		return PUNIT_SEMAPHORE_CHT;
+	else
+		return PUNIT_SEMAPHORE;
+}
+
 static int get_sem(struct dw_i2c_dev *dev, u32 *sem)
 {
+	u32 addr = get_sem_addr(dev);
 	u32 data;
 	int ret;
 
@@ -41,7 +51,7 @@ static int get_sem(struct dw_i2c_dev *dev, u32 *sem)
 	 */
 	pm_qos_update_request(&dev->pm_qos, 0);
 
-	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data);
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data);
 	if (ret) {
 		dev_err(dev->dev, "iosf failed to read punit semaphore\n");
 		return ret;
@@ -54,15 +64,16 @@ static int get_sem(struct dw_i2c_dev *dev, u32 *sem)
 
 static void reset_semaphore(struct dw_i2c_dev *dev)
 {
+	u32 addr = get_sem_addr(dev);
 	u32 data;
 
-	if (iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &data)) {
+	if (iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data)) {
 		dev_err(dev->dev, "iosf failed to reset punit semaphore during read\n");
 		return;
 	}
 
 	data &= ~PUNIT_SEMAPHORE_BIT;
-	if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, data))
+	if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, data))
 		dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n");
 
 	pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);
@@ -70,6 +81,7 @@ static void reset_semaphore(struct dw_i2c_dev *dev)
 
 static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 {
+	u32 addr = get_sem_addr(dev);
 	u32 sem = PUNIT_SEMAPHORE_ACQUIRE;
 	int ret;
 	unsigned long start, end;
@@ -83,7 +95,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 		return 0;
 
 	/* host driver writes to side band semaphore register */
-	ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, PUNIT_SEMAPHORE, sem);
+	ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, sem);
 	if (ret) {
 		dev_err(dev->dev, "iosf punit semaphore request failed\n");
 		return ret;
@@ -107,7 +119,7 @@ static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 	dev_err(dev->dev, "punit semaphore timed out, resetting\n");
 	reset_semaphore(dev);
 
-	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, PUNIT_SEMAPHORE, &sem);
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &sem);
 	if (ret)
 		dev_err(dev->dev, "iosf failed to read punit semaphore\n");
 	else
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 871970e..cd4a874 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -127,6 +127,8 @@ struct dw_i2c_dev {
 #define ACCESS_16BIT		0x00000002
 #define ACCESS_INTR_MASK	0x00000004
 
+#define MODEL_CHERRYTRAIL	0x00000100
+
 extern int i2c_dw_init(struct dw_i2c_dev *dev);
 extern void i2c_dw_disable(struct dw_i2c_dev *dev);
 extern void i2c_dw_disable_int(struct dw_i2c_dev *dev);
diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 96f8230..4e53a9f 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -45,6 +45,7 @@ enum dw_pci_ctl_id_t {
 	medfield,
 	merrifield,
 	baytrail,
+	cherrytrail,
 	haswell,
 };
 
@@ -63,6 +64,7 @@ struct dw_pci_controller {
 	u32 rx_fifo_depth;
 	u32 clk_khz;
 	u32 functionality;
+	u32 flags;
 	struct dw_scl_sda_cfg *scl_sda_cfg;
 	int (*setup)(struct pci_dev *pdev, struct dw_pci_controller *c);
 };
@@ -174,6 +176,15 @@ static struct dw_pci_controller dw_pci_controllers[] = {
 		.functionality = I2C_FUNC_10BIT_ADDR,
 		.scl_sda_cfg = &hsw_config,
 	},
+	[cherrytrail] = {
+		.bus_num = -1,
+		.bus_cfg = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
+		.tx_fifo_depth = 32,
+		.rx_fifo_depth = 32,
+		.functionality = I2C_FUNC_10BIT_ADDR,
+		.flags = MODEL_CHERRYTRAIL,
+		.scl_sda_cfg = &byt_config,
+	},
 };
 
 #ifdef CONFIG_PM
@@ -241,6 +252,7 @@ static int i2c_dw_pci_probe(struct pci_dev *pdev,
 	dev->base = pcim_iomap_table(pdev)[0];
 	dev->dev = &pdev->dev;
 	dev->irq = pdev->irq;
+	dev->flags |= controller->flags;
 
 	if (controller->setup) {
 		r = controller->setup(pdev, controller);
@@ -321,13 +333,13 @@ static const struct pci_device_id i2_designware_pci_ids[] = {
 	{ PCI_VDEVICE(INTEL, 0x9c61), haswell },
 	{ PCI_VDEVICE(INTEL, 0x9c62), haswell },
 	/* Braswell / Cherrytrail */
-	{ PCI_VDEVICE(INTEL, 0x22C1), baytrail },
-	{ PCI_VDEVICE(INTEL, 0x22C2), baytrail },
-	{ PCI_VDEVICE(INTEL, 0x22C3), baytrail },
-	{ PCI_VDEVICE(INTEL, 0x22C4), baytrail },
-	{ PCI_VDEVICE(INTEL, 0x22C5), baytrail },
-	{ PCI_VDEVICE(INTEL, 0x22C6), baytrail },
-	{ PCI_VDEVICE(INTEL, 0x22C7), baytrail },
+	{ PCI_VDEVICE(INTEL, 0x22C1), cherrytrail },
+	{ PCI_VDEVICE(INTEL, 0x22C2), cherrytrail },
+	{ PCI_VDEVICE(INTEL, 0x22C3), cherrytrail },
+	{ PCI_VDEVICE(INTEL, 0x22C4), cherrytrail },
+	{ PCI_VDEVICE(INTEL, 0x22C5), cherrytrail },
+	{ PCI_VDEVICE(INTEL, 0x22C6), cherrytrail },
+	{ PCI_VDEVICE(INTEL, 0x22C7), cherrytrail },
 	{ 0,}
 };
 MODULE_DEVICE_TABLE(pci, i2_designware_pci_ids);
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index b0a64a2..985c4de 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -123,7 +123,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = {
 	{ "INT3432", 0 },
 	{ "INT3433", 0 },
 	{ "80860F41", 0 },
-	{ "808622C1", 0 },
+	{ "808622C1", MODEL_CHERRYTRAIL },
 	{ "AMD0010", ACCESS_INTR_MASK },
 	{ "AMDI0010", ACCESS_INTR_MASK },
 	{ "AMDI0510", 0 },
-- 
2.9.3

Re: [PATCH v4 4/5] i2c: designware-baytrail: Disallow the CPU to enter C6 or C7 while holding the punit semaphore

[Andy Shevchenko]

On Mon, 2016-12-12 at 22:56 +0100, Hans de Goede wrote:
> On my cherrytrail tablet with axp288 pmic, just doing a bunch of
> repeated
> reads from the pmic, e.g. "i2cdump -y 14 0x34" would lookup the tablet
> in
> 1 - 3 runs guaranteed.
> 
> This seems to be causes by the cpu trying to enter C6 or C7 while we
> hold
> the punit bus semaphore, at which point everything just hangs.
> 
> Avoid this by disallowing the CPU to enter C6 or C7 before acquiring
> the
> punit bus semaphore.
> 

Just a nitpick for abbreviations: pmic -> PMIC, punit -> P-Unit, but I'm
okay with the contents which is more important.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109051

What would be good is to have comments / tags from Len and Ville.

> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Tested-by: Takashi Iwai <tiwai@suse.de>
> ---
> Changes in v2:
> -New patch in v2 of this set
> Changes in v3:
> -Change commit message and comment in the code from "force the CPU to
> C1"
>  to "Disallow the CPU to enter C6 or C7", as the CPU may still be in
> either
>  C0 or C1 with the request pm_qos
> Changes in v4:
> -Rename i2c_dw_eval_lock_support to i2c_dw_probe_lock_support so that
> we can
>  add a matching i2c_dw_remove_lock_support cleanup function
> -Move qm_pos removal to new i2c_dw_remove_lock_support function
> -Move pm_qos_add_request to the end of i2c_dw_probe_lock_support
> ---
>  drivers/i2c/busses/i2c-designware-baytrail.c | 21
> ++++++++++++++++++++-
>  drivers/i2c/busses/i2c-designware-core.h     |  9 +++++++--
>  drivers/i2c/busses/i2c-designware-platdrv.c  |  4 +++-
>  3 files changed, 30 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c
> b/drivers/i2c/busses/i2c-designware-baytrail.c
> index cf02222..95d7013 100644
> --- a/drivers/i2c/busses/i2c-designware-baytrail.c
> +++ b/drivers/i2c/busses/i2c-designware-baytrail.c
> @@ -16,6 +16,7 @@
>  #include <linux/acpi.h>
>  #include <linux/i2c.h>
>  #include <linux/interrupt.h>
> +#include <linux/pm_qos.h>
>  
>  #include <asm/iosf_mbi.h>
>  
> @@ -33,6 +34,13 @@ static int get_sem(struct dw_i2c_dev *dev, u32
> *sem)
>  	u32 data;
>  	int ret;
>  
> +	/*
> +	 * Disallow the CPU to enter C6 or C7 state, entering these
> states
> +	 * requires the punit to talk to the pmic and if this happens
> while
> +	 * we're holding the semaphore, the SoC hangs.
> +	 */
> +	pm_qos_update_request(&dev->pm_qos, 0);
> +
>  	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ,
> PUNIT_SEMAPHORE, &data);
>  	if (ret) {
>  		dev_err(dev->dev, "iosf failed to read punit
> semaphore\n");
> @@ -56,6 +64,8 @@ static void reset_semaphore(struct dw_i2c_dev *dev)
>  	data &= ~PUNIT_SEMAPHORE_BIT;
>  	if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE,
> PUNIT_SEMAPHORE, data))
>  		dev_err(dev->dev, "iosf failed to reset punit
> semaphore during write\n");
> +
> +	pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);
>  }
>  
>  static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
> @@ -121,7 +131,7 @@ static void baytrail_i2c_release(struct dw_i2c_dev
> *dev)
>  		jiffies_to_msecs(jiffies - acquired));
>  }
>  
> -int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
> +int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev)
>  {
>  	acpi_status status;
>  	unsigned long long shared_host = 0;
> @@ -149,5 +159,14 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev
> *dev)
>  	dev->release_lock = baytrail_i2c_release;
>  	dev->pm_runtime_disabled = true;
>  
> +	pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY,
> +			   PM_QOS_DEFAULT_VALUE);
> +
>  	return 0;
>  }
> +
> +void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev)
> +{
> +	if (dev->acquire_lock)
> +		pm_qos_remove_request(&dev->pm_qos);
> +}
> diff --git a/drivers/i2c/busses/i2c-designware-core.h
> b/drivers/i2c/busses/i2c-designware-core.h
> index fb143f5..871970e 100644
> --- a/drivers/i2c/busses/i2c-designware-core.h
> +++ b/drivers/i2c/busses/i2c-designware-core.h
> @@ -22,6 +22,7 @@
>   *
>   */
>  
> +#include <linux/pm_qos.h>
>  
>  #define DW_IC_CON_MASTER		0x1
>  #define DW_IC_CON_SPEED_STD		0x2
> @@ -67,6 +68,7 @@
>   * @fp_lcnt: fast plus LCNT value
>   * @hs_hcnt: high speed HCNT value
>   * @hs_lcnt: high speed LCNT value
> + * @pm_qos: pm_qos_request used while holding a hardware lock on the
> bus
>   * @acquire_lock: function to acquire a hardware lock on the bus
>   * @release_lock: function to release a hardware lock on the bus
>   * @pm_runtime_disabled: true if pm runtime is disabled
> @@ -114,6 +116,7 @@ struct dw_i2c_dev {
>  	u16			fp_lcnt;
>  	u16			hs_hcnt;
>  	u16			hs_lcnt;
> +	struct pm_qos_request	pm_qos;
>  	int			(*acquire_lock)(struct dw_i2c_dev
> *dev);
>  	void			(*release_lock)(struct dw_i2c_dev
> *dev);
>  	bool			pm_runtime_disabled;
> @@ -131,7 +134,9 @@ extern u32 i2c_dw_read_comp_param(struct
> dw_i2c_dev *dev);
>  extern int i2c_dw_probe(struct dw_i2c_dev *dev);
>  
>  #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
> -extern int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev);
> +extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);
> +extern void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev);
>  #else
> -static inline int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) {
> return 0; }
> +static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) {
> return 0; }
> +static inline void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev)
> {}
>  #endif
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
> b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 97a2ca1..b0a64a2 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -210,7 +210,7 @@ static int dw_i2c_plat_probe(struct
> platform_device *pdev)
>  		return -EINVAL;
>  	}
>  
> -	r = i2c_dw_eval_lock_support(dev);
> +	r = i2c_dw_probe_lock_support(dev);
>  	if (r)
>  		return r;
>  
> @@ -291,6 +291,8 @@ static int dw_i2c_plat_remove(struct
> platform_device *pdev)
>  	if (!dev->pm_runtime_disabled)
>  		pm_runtime_disable(&pdev->dev);
>  
> +	i2c_dw_remove_lock_support(dev);
> +
>  	return 0;
>  }
>  

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Re: [PATCH v4 4/5] i2c: designware-baytrail: Disallow the CPU to enter C6 or C7 while holding the punit semaphore

[Hans de Goede]

Hi,

On 13-12-16 10:56, Andy Shevchenko wrote:
> On Mon, 2016-12-12 at 22:56 +0100, Hans de Goede wrote:
>> On my cherrytrail tablet with axp288 pmic, just doing a bunch of
>> repeated
>> reads from the pmic, e.g. "i2cdump -y 14 0x34" would lookup the tablet
>> in
>> 1 - 3 runs guaranteed.
>>
>> This seems to be causes by the cpu trying to enter C6 or C7 while we
>> hold
>> the punit bus semaphore, at which point everything just hangs.
>>
>> Avoid this by disallowing the CPU to enter C6 or C7 before acquiring
>> the
>> punit bus semaphore.
>>
>
> Just a nitpick for abbreviations: pmic -> PMIC, punit -> P-Unit, but I'm
> okay with the contents which is more important.

Erm, the rest of the code, including dev_info and dev_err messages
also uses punit without the - in there, anyways not planning to
send a v5 for now.

> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Thank you.

>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109051
>
> What would be good is to have comments / tags from Len and Ville.

About this patch vs bug bko109051, yesterday I've spend time reading
that entire bug. It seems it is a combination of at least 3 bugs
combined, 2 i915 related with commits which seem to trigger
the problem (2 different groups of users with a different problem
it seems) which causes a hang every few hours. And one other
bug where the system freezes in minutes, that one sounds like
what I was seeing without this patch (but may well be yet
another issue).

As for the 2 i915 bugs, there have been git bisects for both of
them, it would be good if someone could take a look at these, just
search for bisect in that huge bug.

Regards,

Hans




>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> Tested-by: Takashi Iwai <tiwai@suse.de>
>> ---
>> Changes in v2:
>> -New patch in v2 of this set
>> Changes in v3:
>> -Change commit message and comment in the code from "force the CPU to
>> C1"
>>  to "Disallow the CPU to enter C6 or C7", as the CPU may still be in
>> either
>>  C0 or C1 with the request pm_qos
>> Changes in v4:
>> -Rename i2c_dw_eval_lock_support to i2c_dw_probe_lock_support so that
>> we can
>>  add a matching i2c_dw_remove_lock_support cleanup function
>> -Move qm_pos removal to new i2c_dw_remove_lock_support function
>> -Move pm_qos_add_request to the end of i2c_dw_probe_lock_support
>> ---
>>  drivers/i2c/busses/i2c-designware-baytrail.c | 21
>> ++++++++++++++++++++-
>>  drivers/i2c/busses/i2c-designware-core.h     |  9 +++++++--
>>  drivers/i2c/busses/i2c-designware-platdrv.c  |  4 +++-
>>  3 files changed, 30 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c
>> b/drivers/i2c/busses/i2c-designware-baytrail.c
>> index cf02222..95d7013 100644
>> --- a/drivers/i2c/busses/i2c-designware-baytrail.c
>> +++ b/drivers/i2c/busses/i2c-designware-baytrail.c
>> @@ -16,6 +16,7 @@
>>  #include <linux/acpi.h>
>>  #include <linux/i2c.h>
>>  #include <linux/interrupt.h>
>> +#include <linux/pm_qos.h>
>>
>>  #include <asm/iosf_mbi.h>
>>
>> @@ -33,6 +34,13 @@ static int get_sem(struct dw_i2c_dev *dev, u32
>> *sem)
>>  	u32 data;
>>  	int ret;
>>
>> +	/*
>> +	 * Disallow the CPU to enter C6 or C7 state, entering these
>> states
>> +	 * requires the punit to talk to the pmic and if this happens
>> while
>> +	 * we're holding the semaphore, the SoC hangs.
>> +	 */
>> +	pm_qos_update_request(&dev->pm_qos, 0);
>> +
>>  	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ,
>> PUNIT_SEMAPHORE, &data);
>>  	if (ret) {
>>  		dev_err(dev->dev, "iosf failed to read punit
>> semaphore\n");
>> @@ -56,6 +64,8 @@ static void reset_semaphore(struct dw_i2c_dev *dev)
>>  	data &= ~PUNIT_SEMAPHORE_BIT;
>>  	if (iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE,
>> PUNIT_SEMAPHORE, data))
>>  		dev_err(dev->dev, "iosf failed to reset punit
>> semaphore during write\n");
>> +
>> +	pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);
>>  }
>>
>>  static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
>> @@ -121,7 +131,7 @@ static void baytrail_i2c_release(struct dw_i2c_dev
>> *dev)
>>  		jiffies_to_msecs(jiffies - acquired));
>>  }
>>
>> -int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
>> +int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev)
>>  {
>>  	acpi_status status;
>>  	unsigned long long shared_host = 0;
>> @@ -149,5 +159,14 @@ int i2c_dw_eval_lock_support(struct dw_i2c_dev
>> *dev)
>>  	dev->release_lock = baytrail_i2c_release;
>>  	dev->pm_runtime_disabled = true;
>>
>> +	pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY,
>> +			   PM_QOS_DEFAULT_VALUE);
>> +
>>  	return 0;
>>  }
>> +
>> +void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev)
>> +{
>> +	if (dev->acquire_lock)
>> +		pm_qos_remove_request(&dev->pm_qos);
>> +}
>> diff --git a/drivers/i2c/busses/i2c-designware-core.h
>> b/drivers/i2c/busses/i2c-designware-core.h
>> index fb143f5..871970e 100644
>> --- a/drivers/i2c/busses/i2c-designware-core.h
>> +++ b/drivers/i2c/busses/i2c-designware-core.h
>> @@ -22,6 +22,7 @@
>>   *
>>   */
>>
>> +#include <linux/pm_qos.h>
>>
>>  #define DW_IC_CON_MASTER		0x1
>>  #define DW_IC_CON_SPEED_STD		0x2
>> @@ -67,6 +68,7 @@
>>   * @fp_lcnt: fast plus LCNT value
>>   * @hs_hcnt: high speed HCNT value
>>   * @hs_lcnt: high speed LCNT value
>> + * @pm_qos: pm_qos_request used while holding a hardware lock on the
>> bus
>>   * @acquire_lock: function to acquire a hardware lock on the bus
>>   * @release_lock: function to release a hardware lock on the bus
>>   * @pm_runtime_disabled: true if pm runtime is disabled
>> @@ -114,6 +116,7 @@ struct dw_i2c_dev {
>>  	u16			fp_lcnt;
>>  	u16			hs_hcnt;
>>  	u16			hs_lcnt;
>> +	struct pm_qos_request	pm_qos;
>>  	int			(*acquire_lock)(struct dw_i2c_dev
>> *dev);
>>  	void			(*release_lock)(struct dw_i2c_dev
>> *dev);
>>  	bool			pm_runtime_disabled;
>> @@ -131,7 +134,9 @@ extern u32 i2c_dw_read_comp_param(struct
>> dw_i2c_dev *dev);
>>  extern int i2c_dw_probe(struct dw_i2c_dev *dev);
>>
>>  #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
>> -extern int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev);
>> +extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);
>> +extern void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev);
>>  #else
>> -static inline int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) {
>> return 0; }
>> +static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) {
>> return 0; }
>> +static inline void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev)
>> {}
>>  #endif
>> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
>> b/drivers/i2c/busses/i2c-designware-platdrv.c
>> index 97a2ca1..b0a64a2 100644
>> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
>> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
>> @@ -210,7 +210,7 @@ static int dw_i2c_plat_probe(struct
>> platform_device *pdev)
>>  		return -EINVAL;
>>  	}
>>
>> -	r = i2c_dw_eval_lock_support(dev);
>> +	r = i2c_dw_probe_lock_support(dev);
>>  	if (r)
>>  		return r;
>>
>> @@ -291,6 +291,8 @@ static int dw_i2c_plat_remove(struct
>> platform_device *pdev)
>>  	if (!dev->pm_runtime_disabled)
>>  		pm_runtime_disable(&pdev->dev);
>>
>> +	i2c_dw_remove_lock_support(dev);
>> +
>>  	return 0;
>>  }
>>
>

Re: [PATCH v4 4/5] i2c: designware-baytrail: Disallow the CPU to enter C6 or C7 while holding the punit semaphore

[Andy Shevchenko]

On Tue, 2016-12-13 at 13:21 +0100, Hans de Goede wrote:
> Hi,
> 
> On 13-12-16 10:56, Andy Shevchenko wrote:
> > On Mon, 2016-12-12 at 22:56 +0100, Hans de Goede wrote:
> > > On my cherrytrail tablet with axp288 pmic, just doing a bunch of
> > > repeated
> > > reads from the pmic, e.g. "i2cdump -y 14 0x34" would lookup the
> > > tablet
> > > in
> > > 1 - 3 runs guaranteed.
> > > 
> > > This seems to be causes by the cpu trying to enter C6 or C7 while
> > > we
> > > hold
> > > the punit bus semaphore, at which point everything just hangs.
> > > 
> > > Avoid this by disallowing the CPU to enter C6 or C7 before
> > > acquiring
> > > the
> > > punit bus semaphore.
> > > 
> > 
> > Just a nitpick for abbreviations: pmic -> PMIC, punit -> P-Unit, but
> > I'm
> > okay with the contents which is more important.
> 
> Erm, the rest of the code, including dev_info and dev_err messages
> also uses punit without the - in there, anyways not planning to
> send a v5 for now.

Yes, no need in v5 until something more serious comes up.

> 
> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> Thank you.
> 
> > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109051
> > 
> > What would be good is to have comments / tags from Len and Ville.
> 
> About this patch vs bug bko109051, yesterday I've spend time reading
> that entire bug. It seems it is a combination of at least 3 bugs
> combined, 2 i915 related with commits which seem to trigger
> the problem (2 different groups of users with a different problem
> it seems) which causes a hang every few hours. And one other
> bug where the system freezes in minutes, that one sounds like
> what I was seeing without this patch (but may well be yet
> another issue).

There also a dw_dmac bug which I fixed, but people are still referring
to it in that bug report.

> 
> As for the 2 i915 bugs, there have been git bisects for both of
> them, it would be good if someone could take a look at these, just
> search for bisect in that huge bug.

Agreed.

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

Re: [PATCH v4 4/5] i2c: designware-baytrail: Disallow the CPU to enter C6 or C7 while holding the punit semaphore

[Jarkko Nikula]

On 12/13/2016 11:56 AM, Andy Shevchenko wrote:
> On Mon, 2016-12-12 at 22:56 +0100, Hans de Goede wrote:
>> On my cherrytrail tablet with axp288 pmic, just doing a bunch of
>> repeated
>> reads from the pmic, e.g. "i2cdump -y 14 0x34" would lookup the tablet
>> in
>> 1 - 3 runs guaranteed.
>>
>> This seems to be causes by the cpu trying to enter C6 or C7 while we
>> hold
>> the punit bus semaphore, at which point everything just hangs.
>>
>> Avoid this by disallowing the CPU to enter C6 or C7 before acquiring
>> the
>> punit bus semaphore.
>>
>
> Just a nitpick for abbreviations: pmic -> PMIC, punit -> P-Unit, but I'm
> okay with the contents which is more important.
>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>
No need for v5 from my side either (Andy agreed it later in the thread)

Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

>> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109051
>
> What would be good is to have comments / tags from Len and Ville.
>
We can have also follow up patch if some other PM QoS acrobatics are 
required than what's implemented here. Getting real bug fixed is quite 
big benefit.

Re: [PATCH v4 5/5] i2c: designware-baytrail: Add support for cherrytrail

[Jarkko Nikula]

On 12/12/2016 11:56 PM, Hans de Goede wrote:
> The cherrytrail punit has the pmic i2c bus access semaphore at a
> different register address.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Reviewed-by: Takashi Iwai <tiwai@suse.de>
> Tested-by: Takashi Iwai <tiwai@suse.de>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> Changes in v2:
> -Adjust for accessor_flags -> flags rename
> -Add flags field to struct dw_pci_controller
> -Add get_sem_addr() helper replacing MODEL_CHERRYTRAIL flag checking in
>  PUNIT_SEMAPHORE macro
> Changes in v3:
> -Add a gap between ACCESS_* and MODEL_* flags as reserved space for
>  future ACCESS_* flags
> Changes in v4:
> -s/CHV/CHT/
> ---
>  drivers/i2c/busses/i2c-designware-baytrail.c | 22 +++++++++++++++++-----
>  drivers/i2c/busses/i2c-designware-core.h     |  2 ++
>  drivers/i2c/busses/i2c-designware-pcidrv.c   | 26 +++++++++++++++++++-------
>  drivers/i2c/busses/i2c-designware-platdrv.c  |  2 +-
>  4 files changed, 39 insertions(+), 13 deletions(-)
>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>