From 9c4ba9466117b16a2b85034bb87db528aaeb3f07 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Tue, 10 Aug 2010 18:02:24 -0700 Subject: gpiolib: decouple might_sleep_if() from DEBUG Be more consistent about runtime programming interface abuse warnings, which can reduce some confusion and trigger bugfixes. Based on an observation and patch from Jani Nikula. Also update doc to highlight some sleeping-call issues and to match some recent changes. Signed-off-by: David Brownell Cc: Jani Nikula Cc: "Ryan Mallon" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/gpiolib.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 6a6bd569e1f8..1a8c18cbf201 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1272,7 +1272,7 @@ void gpio_free(unsigned gpio) if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { if (chip->free) { spin_unlock_irqrestore(&gpio_lock, flags); - might_sleep_if(extra_checks && chip->can_sleep); + might_sleep_if(chip->can_sleep); chip->free(chip, gpio - chip->base); spin_lock_irqsave(&gpio_lock, flags); } @@ -1410,7 +1410,7 @@ int gpio_direction_input(unsigned gpio) spin_unlock_irqrestore(&gpio_lock, flags); - might_sleep_if(extra_checks && chip->can_sleep); + might_sleep_if(chip->can_sleep); if (status) { status = chip->request(chip, gpio); @@ -1463,7 +1463,7 @@ int gpio_direction_output(unsigned gpio, int value) spin_unlock_irqrestore(&gpio_lock, flags); - might_sleep_if(extra_checks && chip->can_sleep); + might_sleep_if(chip->can_sleep); if (status) { status = chip->request(chip, gpio); @@ -1521,7 +1521,7 @@ int gpio_set_debounce(unsigned gpio, unsigned debounce) spin_unlock_irqrestore(&gpio_lock, flags); - might_sleep_if(extra_checks && chip->can_sleep); + might_sleep_if(chip->can_sleep); return chip->set_debounce(chip, gpio, debounce); @@ -1571,7 +1571,7 @@ int __gpio_get_value(unsigned gpio) struct gpio_chip *chip; chip = gpio_to_chip(gpio); - WARN_ON(extra_checks && chip->can_sleep); + WARN_ON(chip->can_sleep); return chip->get ? chip->get(chip, gpio - chip->base) : 0; } EXPORT_SYMBOL_GPL(__gpio_get_value); @@ -1590,7 +1590,7 @@ void __gpio_set_value(unsigned gpio, int value) struct gpio_chip *chip; chip = gpio_to_chip(gpio); - WARN_ON(extra_checks && chip->can_sleep); + WARN_ON(chip->can_sleep); chip->set(chip, gpio - chip->base, value); } EXPORT_SYMBOL_GPL(__gpio_set_value); -- cgit v1.2.2 From 5ba1821d1b4a506f8c9be93d962f22b24b6140a5 Mon Sep 17 00:00:00 2001 From: Daniel Gl?ckner Date: Tue, 10 Aug 2010 18:02:25 -0700 Subject: gpiolib: get rid of struct poll_desc and worklet As sysfs_notify_dirent has been made irq safe, there is no reason to not call it directly from irq. With the work_struct removed, the remaining element in poll_desc is a sysfs_dirent pointer which may not be NULL. We can therefore store it directly in the idr and pass it as context to the irq handler. Most part of the patch deals with renaming defines and variables to reflect their new use without functional change. I also took the opportunity to initialize the idr statically. Signed-off-by: Daniel Gl?ckner Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/gpiolib.c | 80 +++++++++++++++++--------------------------------- 1 file changed, 27 insertions(+), 53 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 1a8c18cbf201..8a29404985f1 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -57,9 +57,9 @@ struct gpio_desc { #define FLAG_TRIG_RISE 6 /* trigger on rising edge */ #define FLAG_ACTIVE_LOW 7 /* sysfs value has active low */ -#define PDESC_ID_SHIFT 16 /* add new flags before this one */ +#define ID_SHIFT 16 /* add new flags before this one */ -#define GPIO_FLAGS_MASK ((1 << PDESC_ID_SHIFT) - 1) +#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1) #define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE)) #ifdef CONFIG_DEBUG_FS @@ -69,12 +69,7 @@ struct gpio_desc { static struct gpio_desc gpio_desc[ARCH_NR_GPIOS]; #ifdef CONFIG_GPIO_SYSFS -struct poll_desc { - struct work_struct work; - struct sysfs_dirent *value_sd; -}; - -static struct idr pdesc_idr; +static DEFINE_IDR(dirent_idr); #endif static inline void desc_set_label(struct gpio_desc *d, const char *label) @@ -325,24 +320,16 @@ static const DEVICE_ATTR(value, 0644, static irqreturn_t gpio_sysfs_irq(int irq, void *priv) { - struct work_struct *work = priv; + struct sysfs_dirent *value_sd = priv; - schedule_work(work); + sysfs_notify_dirent(value_sd); return IRQ_HANDLED; } -static void gpio_notify_sysfs(struct work_struct *work) -{ - struct poll_desc *pdesc; - - pdesc = container_of(work, struct poll_desc, work); - sysfs_notify_dirent(pdesc->value_sd); -} - static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, unsigned long gpio_flags) { - struct poll_desc *pdesc; + struct sysfs_dirent *value_sd; unsigned long irq_flags; int ret, irq, id; @@ -353,18 +340,16 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, if (irq < 0) return -EIO; - id = desc->flags >> PDESC_ID_SHIFT; - pdesc = idr_find(&pdesc_idr, id); - if (pdesc) { - free_irq(irq, &pdesc->work); - cancel_work_sync(&pdesc->work); - } + id = desc->flags >> ID_SHIFT; + value_sd = idr_find(&dirent_idr, id); + if (value_sd) + free_irq(irq, value_sd); desc->flags &= ~GPIO_TRIGGER_MASK; if (!gpio_flags) { ret = 0; - goto free_sd; + goto free_id; } irq_flags = IRQF_SHARED; @@ -375,55 +360,46 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; - if (!pdesc) { - pdesc = kmalloc(sizeof(*pdesc), GFP_KERNEL); - if (!pdesc) { - ret = -ENOMEM; + if (!value_sd) { + value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); + if (!value_sd) { + ret = -ENODEV; goto err_out; } do { ret = -ENOMEM; - if (idr_pre_get(&pdesc_idr, GFP_KERNEL)) - ret = idr_get_new_above(&pdesc_idr, - pdesc, 1, &id); + if (idr_pre_get(&dirent_idr, GFP_KERNEL)) + ret = idr_get_new_above(&dirent_idr, value_sd, + 1, &id); } while (ret == -EAGAIN); if (ret) - goto free_mem; + goto free_sd; desc->flags &= GPIO_FLAGS_MASK; - desc->flags |= (unsigned long)id << PDESC_ID_SHIFT; + desc->flags |= (unsigned long)id << ID_SHIFT; - if (desc->flags >> PDESC_ID_SHIFT != id) { + if (desc->flags >> ID_SHIFT != id) { ret = -ERANGE; goto free_id; } - - pdesc->value_sd = sysfs_get_dirent(dev->kobj.sd, NULL, "value"); - if (!pdesc->value_sd) { - ret = -ENODEV; - goto free_id; - } - INIT_WORK(&pdesc->work, gpio_notify_sysfs); } ret = request_irq(irq, gpio_sysfs_irq, irq_flags, - "gpiolib", &pdesc->work); + "gpiolib", value_sd); if (ret) - goto free_sd; + goto free_id; desc->flags |= gpio_flags; return 0; -free_sd: - if (pdesc) - sysfs_put(pdesc->value_sd); free_id: - idr_remove(&pdesc_idr, id); + idr_remove(&dirent_idr, id); desc->flags &= GPIO_FLAGS_MASK; -free_mem: - kfree(pdesc); +free_sd: + if (value_sd) + sysfs_put(value_sd); err_out: return ret; } @@ -994,8 +970,6 @@ static int __init gpiolib_sysfs_init(void) unsigned long flags; unsigned gpio; - idr_init(&pdesc_idr); - status = class_register(&gpio_class); if (status < 0) return status; -- cgit v1.2.2 From 364fadb32b67695cec610f5cd03df2514ef0f2b0 Mon Sep 17 00:00:00 2001 From: Daniel Gl?ckner Date: Tue, 10 Aug 2010 18:02:26 -0700 Subject: gpiolib: allow nested threaded irqs for poll(2) The pca953x driver requires the use of threaded irqs as its irq demultiplexer can sleep. Our irq handler can be called from any context, so use request_any_context_irq to allow threaded irqs as well. Signed-off-by: Daniel Gl?ckner Reported-by: Ian Jeffray Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/gpiolib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 8a29404985f1..21da9c19a0cb 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -386,9 +386,9 @@ static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev, } } - ret = request_irq(irq, gpio_sysfs_irq, irq_flags, + ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags, "gpiolib", value_sd); - if (ret) + if (ret < 0) goto free_id; desc->flags |= gpio_flags; -- cgit v1.2.2