Messages in this thread Patch in this message | | | Subject | Re: [PATCH 3/12] LED: Add LED Trigger Support | From | Richard Purdie <> | Date | Wed, 08 Feb 2006 02:37:21 +0000 |
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LED trigger support fixes.
Split the locking on struct led_classdev into LED and trigger sections to prevent potential deadlock. Fix a bug introduced in -mm where leds.h can be included more than once causing compile errors. Make use of class_get_devdata()
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Index: linux-2.6.15/drivers/leds/led-class.c =================================================================== --- linux-2.6.15.orig/drivers/leds/led-class.c 2006-02-08 01:20:41.000000000 +0000 +++ linux-2.6.15/drivers/leds/led-class.c 2006-02-08 01:20:51.000000000 +0000 @@ -106,18 +106,20 @@ class_device_create_file(led_cdev->class_dev, &class_device_attr_brightness); -#ifdef CONFIG_LEDS_TRIGGERS - class_device_create_file(led_cdev->class_dev, - &class_device_attr_trigger); -#endif - /* add to the list of leds */ write_lock(&leds_list_lock); list_add_tail(&led_cdev->node, &leds_list); write_unlock(&leds_list_lock); +#ifdef CONFIG_LEDS_TRIGGERS + rwlock_init(&led_cdev->trigger_lock); + led_trigger_set_default(led_cdev); + class_device_create_file(led_cdev->class_dev, + &class_device_attr_trigger); +#endif + printk(KERN_INFO "Registered led device: %s\n", led_cdev->class_dev->class_id); @@ -138,10 +140,12 @@ #ifdef CONFIG_LEDS_TRIGGERS class_device_remove_file(led_cdev->class_dev, &class_device_attr_trigger); -#endif + write_lock(&led_cdev->trigger_lock); if (led_cdev->trigger) led_trigger_set(led_cdev, NULL); + write_unlock(&led_cdev->trigger_lock); +#endif class_device_unregister(led_cdev->class_dev); Index: linux-2.6.15/drivers/leds/led-triggers.c =================================================================== --- linux-2.6.15.orig/drivers/leds/led-triggers.c 2006-02-08 01:20:50.000000000 +0000 +++ linux-2.6.15/drivers/leds/led-triggers.c 2006-02-08 01:20:51.000000000 +0000 @@ -24,7 +24,7 @@ #include "leds.h" /* - * Nests outside led_cdev->lock + * Nests outside led_cdev->lock and led_cdev->trigger_lock */ static rwlock_t triggers_list_lock = RW_LOCK_UNLOCKED; static LIST_HEAD(trigger_list); @@ -32,7 +32,7 @@ ssize_t led_trigger_store(struct class_device *dev, const char *buf, size_t count) { - struct led_classdev *led_cdev = dev->class_data; + struct led_classdev *led_cdev = class_get_devdata(dev); char trigger_name[TRIG_NAME_MAX]; struct led_trigger *trig; size_t len; @@ -45,18 +45,18 @@ trigger_name[len - 1] = '\0'; if (!strcmp(trigger_name, "none")) { - write_lock(&led_cdev->lock); + write_lock(&led_cdev->trigger_lock); led_trigger_set(led_cdev, NULL); - write_unlock(&led_cdev->lock); + write_unlock(&led_cdev->trigger_lock); return count; } read_lock(&triggers_list_lock); list_for_each_entry(trig, &trigger_list, next_trig) { if (!strcmp(trigger_name, trig->name)) { - write_lock(&led_cdev->lock); + write_lock(&led_cdev->trigger_lock); led_trigger_set(led_cdev, trig); - write_unlock(&led_cdev->lock); + write_unlock(&led_cdev->trigger_lock); read_unlock(&triggers_list_lock); return count; @@ -70,12 +70,12 @@ ssize_t led_trigger_show(struct class_device *dev, char *buf) { - struct led_classdev *led_cdev = dev->class_data; + struct led_classdev *led_cdev = class_get_devdata(dev); struct led_trigger *trig; int len = 0; read_lock(&triggers_list_lock); - read_lock(&led_cdev->lock); + read_lock(&led_cdev->trigger_lock); if (!led_cdev->trigger) len += sprintf(buf+len, "[none] "); @@ -89,7 +89,7 @@ else len += sprintf(buf+len, "%s ", trig->name); } - read_unlock(&led_cdev->lock); + read_unlock(&led_cdev->trigger_lock); read_unlock(&triggers_list_lock); len += sprintf(len+buf, "\n"); @@ -116,7 +116,7 @@ read_unlock(&trigger->leddev_list_lock); } -/* Caller must ensure led_cdev->lock held for write */ +/* Caller must ensure led_cdev->trigger_lock held */ void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger) { /* Remove any existing trigger */ @@ -126,7 +126,6 @@ write_unlock(&led_cdev->trigger->leddev_list_lock); if (led_cdev->trigger->deactivate) led_cdev->trigger->deactivate(led_cdev); - } if (trigger) { write_lock(&trigger->leddev_list_lock); @@ -146,12 +145,12 @@ return; read_lock(&triggers_list_lock); - write_lock(&led_cdev->lock); + write_lock(&led_cdev->trigger_lock); list_for_each_entry(trig, &trigger_list, next_trig) { if (!strcmp(led_cdev->default_trigger, trig->name)) led_trigger_set(led_cdev, trig); } - write_unlock(&led_cdev->lock); + write_unlock(&led_cdev->trigger_lock); read_unlock(&triggers_list_lock); } @@ -170,11 +169,11 @@ /* Register with any LEDs that have this as a default trigger */ read_lock(&leds_list_lock); list_for_each_entry(led_cdev, &leds_list, node) { - write_lock(&led_cdev->lock); + write_lock(&led_cdev->trigger_lock); if (!led_cdev->trigger && led_cdev->default_trigger && !strcmp(led_cdev->default_trigger, trigger->name)) led_trigger_set(led_cdev, trigger); - write_unlock(&led_cdev->lock); + write_unlock(&led_cdev->trigger_lock); } read_unlock(&leds_list_lock); @@ -206,10 +205,10 @@ /* Remove anyone actively using this trigger */ read_lock(&leds_list_lock); list_for_each_entry(led_cdev, &leds_list, node) { - write_lock(&led_cdev->lock); + write_lock(&led_cdev->trigger_lock); if (led_cdev->trigger == trigger) led_trigger_set(led_cdev, NULL); - write_unlock(&led_cdev->lock); + write_unlock(&led_cdev->trigger_lock); } read_unlock(&leds_list_lock); } Index: linux-2.6.15/include/linux/leds.h =================================================================== --- linux-2.6.15.orig/include/linux/leds.h 2006-02-08 01:20:41.000000000 +0000 +++ linux-2.6.15/include/linux/leds.h 2006-02-08 01:21:54.000000000 +0000 @@ -10,6 +10,9 @@ * */ +#ifndef _LINUX_LEDS +#define _LINUX_LEDS + struct device; struct class_device; /* @@ -36,16 +39,19 @@ /* LED Device linked list */ struct list_head node; + /* Protects the LED properties data above */ + rwlock_t lock; + /* Trigger data */ char *default_trigger; #ifdef CONFIG_LEDS_TRIGGERS + rwlock_t trigger_lock; + /* Protects the trigger data below */ + struct led_trigger *trigger; struct list_head trig_list; void *trigger_data; #endif - - /* This protects the data in this structure */ - rwlock_t lock; }; extern int led_classdev_register(struct device *parent, @@ -98,3 +104,5 @@ #define led_trigger_event(x, y) do {} while(0) #endif + +#endif /* _LINUX_LEDS */
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