gpio: gpio-ml-ioh: Use spinlock for register access protection

PATCH Applied Axel Lin 3 participants 7 messages Jul 29, 2012 – Aug 14, 2012

Subsystems (2)

GPIO Intel GPIO drivers

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Axel Lin

author

2012-07-29 02:54 UTC #0 lore raw

PATCH 1/2 gpio: gpio-ml-ioh: Use spinlock for register access protection

gpio_chip.can_sleep is 0, but current code uses mutex in ioh_gpio_set, ioh_gpio_get and ioh_gpio_direction_input functions.
Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock.

Signed-off-by Axel Lin <[email protected]>

---
 drivers/gpio/gpio-ml-ioh.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

drivers/gpio/gpio-ml-ioh.c +10 ~~-10~~

index db01f15..6a29ee1 100644
@@ -87,8 +87,7 @@ struct ioh_gpio_reg_data {
  * @gpio_use_sel:		Save GPIO_USE_SEL1~4 register for PM
  * @ch:				Indicate GPIO channel
  * @irq_base:		Save base of IRQ number for interrupt
- * @spinlock:		Used for register access protection in
- *				interrupt context ioh_irq_type and PM;
+ * @spinlock:		Used for register access protection
  */
 struct ioh_gpio {
 	void __iomem *base;

@@ -97,7 +96,6 @@ struct ioh_gpio {
 	struct gpio_chip gpio;
 	struct ioh_gpio_reg_data ioh_gpio_reg;
 	u32 gpio_use_sel;
-	struct mutex lock;
 	int ch;
 	int irq_base;
 	spinlock_t spinlock;

@@ -109,8 +107,9 @@ static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
 {
 	u32 reg_val;
 	struct ioh_gpio *chip =	container_of(gpio, struct ioh_gpio, gpio);
+	unsigned long flags;
 
-	mutex_lock(&chip->lock);
+	spin_lock_irqsave(&chip->spinlock, flags);
 	reg_val = ioread32(&chip->reg->regs[chip->ch].po);
 	if (val)
 		reg_val |= (1 << nr);

@@ -118,7 +117,7 @@ static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
 		reg_val &= ~(1 << nr);
 
 	iowrite32(reg_val, &chip->reg->regs[chip->ch].po);
-	mutex_unlock(&chip->lock);
+	spin_unlock_irqrestore(&chip->spinlock, flags);
 }
 
 static int ioh_gpio_get(struct gpio_chip *gpio, unsigned nr)

@@ -134,8 +133,9 @@ static int ioh_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
 	struct ioh_gpio *chip =	container_of(gpio, struct ioh_gpio, gpio);
 	u32 pm;
 	u32 reg_val;
+	unsigned long flags;
 
-	mutex_lock(&chip->lock);
+	spin_lock_irqsave(&chip->spinlock, flags);
 	pm = ioread32(&chip->reg->regs[chip->ch].pm) &
 					((1 << num_ports[chip->ch]) - 1);
 	pm |= (1 << nr);

@@ -148,7 +148,7 @@ static int ioh_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
 		reg_val &= ~(1 << nr);
 	iowrite32(reg_val, &chip->reg->regs[chip->ch].po);
 
-	mutex_unlock(&chip->lock);
+	spin_unlock_irqrestore(&chip->spinlock, flags);
 
 	return 0;
 }

@@ -157,13 +157,14 @@ static int ioh_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
 {
 	struct ioh_gpio *chip =	container_of(gpio, struct ioh_gpio, gpio);
 	u32 pm;
+	unsigned long flags;
 
-	mutex_lock(&chip->lock);
+	spin_lock_irqsave(&chip->spinlock, flags);
 	pm = ioread32(&chip->reg->regs[chip->ch].pm) &
 				((1 << num_ports[chip->ch]) - 1);
 	pm &= ~(1 << nr);
 	iowrite32(pm, &chip->reg->regs[chip->ch].pm);
-	mutex_unlock(&chip->lock);
+	spin_unlock_irqrestore(&chip->spinlock, flags);
 
 	return 0;
 }

@@ -447,7 +448,6 @@ static int __devinit ioh_gpio_probe(struct pci_dev *pdev,
 		chip->base = base;
 		chip->reg = chip->base;
 		chip->ch = i;
-		mutex_init(&chip->lock);
 		spin_lock_init(&chip->spinlock);
 		ioh_gpio_setup(chip, num_ports[i]);
 		ret = gpiochip_add(&chip->gpio);

Signature · 1 line

1.7.9.5

Axel Lin

author

2012-07-29 02:56 UTC #1 lore raw

PATCH 2/2 gpio: gpio-pch: Use spinlock for register access protection

gpio_chip.can_sleep is 0, but current code uses mutex in pch_gpio_set pch_gpio_get and pch_gpio_direction_input functions.
Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock.

Signed-off-by Axel Lin <[email protected]>

---
 drivers/gpio/gpio-pch.c |   22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

drivers/gpio/gpio-pch.c +10 ~~-12~~

index 139ad3e..4ad0c4f 100644
@@ -92,9 +92,7 @@ struct pch_gpio_reg_data {
  * @lock:			Used for register access protection
  * @irq_base:		Save base of IRQ number for interrupt
  * @ioh:		IOH ID
- * @spinlock:		Used for register access protection in
- *				interrupt context pch_irq_mask,
- *				pch_irq_unmask and pch_irq_type;
+ * @spinlock:		Used for register access protection
  */
 struct pch_gpio {
 	void __iomem *base;

@@ -102,7 +100,6 @@ struct pch_gpio {
 	struct device *dev;
 	struct gpio_chip gpio;
 	struct pch_gpio_reg_data pch_gpio_reg;
-	struct mutex lock;
 	int irq_base;
 	enum pch_type_t ioh;
 	spinlock_t spinlock;

@@ -112,8 +109,9 @@ static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
 {
 	u32 reg_val;
 	struct pch_gpio *chip =	container_of(gpio, struct pch_gpio, gpio);
+	unsigned long flags;
 
-	mutex_lock(&chip->lock);
+	spin_lock_irqsave(&chip->spinlock, flags);
 	reg_val = ioread32(&chip->reg->po);
 	if (val)
 		reg_val |= (1 << nr);

@@ -121,7 +119,7 @@ static void pch_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
 		reg_val &= ~(1 << nr);
 
 	iowrite32(reg_val, &chip->reg->po);
-	mutex_unlock(&chip->lock);
+	spin_unlock_irqrestore(&chip->spinlock, flags);
 }
 
 static int pch_gpio_get(struct gpio_chip *gpio, unsigned nr)

@@ -137,8 +135,9 @@ static int pch_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
 	struct pch_gpio *chip =	container_of(gpio, struct pch_gpio, gpio);
 	u32 pm;
 	u32 reg_val;
+	unsigned long flags;
 
-	mutex_lock(&chip->lock);
+	spin_lock_irqsave(&chip->spinlock, flags);
 	pm = ioread32(&chip->reg->pm) & ((1 << gpio_pins[chip->ioh]) - 1);
 	pm |= (1 << nr);
 	iowrite32(pm, &chip->reg->pm);

@@ -149,8 +148,7 @@ static int pch_gpio_direction_output(struct gpio_chip *gpio, unsigned nr,
 	else
 		reg_val &= ~(1 << nr);
 	iowrite32(reg_val, &chip->reg->po);
-
-	mutex_unlock(&chip->lock);
+	spin_unlock_irqrestore(&chip->spinlock, flags);
 
 	return 0;
 }

@@ -159,12 +157,13 @@ static int pch_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
 {
 	struct pch_gpio *chip =	container_of(gpio, struct pch_gpio, gpio);
 	u32 pm;
+	unsigned long flags;
 
-	mutex_lock(&chip->lock);
+	spin_lock_irqsave(&chip->spinlock, flags);
 	pm = ioread32(&chip->reg->pm) & ((1 << gpio_pins[chip->ioh]) - 1);
 	pm &= ~(1 << nr);
 	iowrite32(pm, &chip->reg->pm);
-	mutex_unlock(&chip->lock);
+	spin_unlock_irqrestore(&chip->spinlock, flags);
 
 	return 0;
 }

@@ -387,7 +386,6 @@ static int __devinit pch_gpio_probe(struct pci_dev *pdev,
 
 	chip->reg = chip->base;
 	pci_set_drvdata(pdev, chip);
-	mutex_init(&chip->lock);
 	spin_lock_init(&chip->spinlock);
 	pch_gpio_setup(chip);
 	ret = gpiochip_add(&chip->gpio);

Signature · 1 line

1.7.9.5

Linus Walleij

2012-08-13 12:02 UTC #2 lore raw

Re: [PATCH RFT 2/2] gpio: gpio-pch: Use spinlock for register access protection

Quoted 6 lines · Axel Lin

gpio_chip.can_sleep is 0, but current code uses mutex in pch_gpio_set pch_gpio_get and pch_gpio_direction_input functions.
Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock.
Signed-off-by Axel Lin <[email protected]>

Same with this, yell or I'll apply.

Yours,
Linus Walleij

Linus Walleij

Applied

2012-08-14 22:20 UTC #3 lore raw

Re: [PATCH RFT 2/2] gpio: gpio-pch: Use spinlock for register access protection

In reply to Axel Lin

Quoted 6 lines · Axel Lin

gpio_chip.can_sleep is 0, but current code uses mutex in pch_gpio_set pch_gpio_get and pch_gpio_direction_input functions.
Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock.
Signed-off-by Axel Lin <[email protected]>

Applied to my devel branch for the next merge window...

Yours,
Linus Walleij

Linus Walleij

2012-08-13 12:01 UTC #4 lore raw

In reply to Axel Lin

Quoted 6 lines · Axel Lin

gpio_chip.can_sleep is 0, but current code uses mutex in ioh_gpio_set, ioh_gpio_get and ioh_gpio_direction_input functions.
Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock.
Signed-off-by Axel Lin <[email protected]>

So IOH guys what are you saying about this?

If you say nothing I will apply these patches.

Yours,
Linus Walleij

Feng Tang

2012-08-14 01:31 UTC #5 lore raw

Quoted 10 lines · On Mon, 13 Aug 2012 14:01:31 +0200 Linus Walleij <[email protected]>…

Quoted 6 lines · Axel Lin
gpio_chip.can_sleep is 0, but current code uses mutex in ioh_gpio_set, ioh_gpio_get and ioh_gpio_direction_input functions.
Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock.
Signed-off-by Axel Lin <[email protected]>
So IOH guys what are you saying about this?

I'm not the IOH guy, but just happened to work on it for some time :) Anyway, the 2 patches both look good to me.

Thanks,
Feng

Linus Walleij

Applied

2012-08-14 22:18 UTC #6 lore raw

In reply to Axel Lin

Quoted 6 lines · Axel Lin

gpio_chip.can_sleep is 0, but current code uses mutex in ioh_gpio_set, ioh_gpio_get and ioh_gpio_direction_input functions.
Thus those functions are not callable from interrupt context. This patch converts mutex into spinlock.
Signed-off-by Axel Lin <[email protected]>

Applied to my devel branch for the next merge window, it doesn't seem like a regression to me atleast.

Yours,
Linus Walleij