| Message ID | 1461881020-13964-2-git-send-email-ezequiel@vanguardiasur.com.ar (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Ezequiel, Thanks for the update. It's indeed reasonable to have all the switching infrastructure in ledtrig-panic.c. I've noticed two minor issues below. On 04/29/2016 12:03 AM, Ezequiel Garcia wrote: > This commit adds a new led_cdev flag LED_PANIC_INDICATOR, which > allows to mark a specific LED to be switched to the "panic" > trigger, on a kernel panic. > > This is useful to allow the user to assign a regular trigger > to a given LED, and still blink that LED on a kernel panic. > > Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> > --- > drivers/leds/led-triggers.c | 2 +- > drivers/leds/leds.h | 1 + > drivers/leds/trigger/Kconfig | 3 +++ > drivers/leds/trigger/ledtrig-panic.c | 47 ++++++++++++++++++++++++++++++++++++ > include/linux/leds.h | 1 + > 5 files changed, 53 insertions(+), 1 deletion(-) > > diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c > index 2181581795d3..55fa65e1ae03 100644 > --- a/drivers/leds/led-triggers.c > +++ b/drivers/leds/led-triggers.c > @@ -26,7 +26,7 @@ > * Nests outside led_cdev->trigger_lock > */ > static DECLARE_RWSEM(triggers_list_lock); > -static LIST_HEAD(trigger_list); > +LIST_HEAD(trigger_list); > > /* Used by LED Class */ > > diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h > index db3f20da7221..7d38e6b9a740 100644 > --- a/drivers/leds/leds.h > +++ b/drivers/leds/leds.h > @@ -30,5 +30,6 @@ void led_set_brightness_nosleep(struct led_classdev *led_cdev, > > extern struct rw_semaphore leds_list_lock; > extern struct list_head leds_list; > +extern struct list_head trigger_list; > > #endif /* __LEDS_H_INCLUDED */ > diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig > index beac8c31c51b..4e4521c9072a 100644 > --- a/drivers/leds/trigger/Kconfig > +++ b/drivers/leds/trigger/Kconfig > @@ -121,6 +121,9 @@ config LEDS_TRIGGER_PANIC > depends on LEDS_TRIGGERS > help > This allows LEDs to be configured to blink on a kernel panic. > + Enabling this option will allow to mark certain LEDs as 'panic-indicators', s/"panic-indicators"/panic indicators/ I understand that you referred here to the DT property name, but this is not obvious at first glance, and it is an implementation detail. > + allowing to blink them on a kernel panic, even if they are set to > + a different trigger. > If unsure, say Y. > > endif # LEDS_TRIGGERS > diff --git a/drivers/leds/trigger/ b/drivers/leds/trigger/ledtrig-panic.c > index 627b350c5ec3..3e447bd2064a 100644 > --- a/drivers/leds/trigger/ledtrig-panic.c > +++ b/drivers/leds/trigger/ledtrig-panic.c > @@ -11,10 +11,54 @@ > > #include <linux/kernel.h> > #include <linux/init.h> > +#include <linux/notifier.h> > #include <linux/leds.h> > +#include "../leds.h" > > static struct led_trigger *trigger; > > +/* > + * This is a called in a special context by the atomic panic s/is a/is/ > + * notifier. This means the trigger can be changed without > + * worrying about locking. > + */ > +static void led_trigger_set_panic(struct led_classdev *led_cdev) > +{ > + struct led_trigger *trig; > + > + list_for_each_entry(trig, &trigger_list, next_trig) { > + if (strcmp("panic", trig->name)) > + continue; > + if (led_cdev->trigger) > + list_del(&led_cdev->trig_list); > + list_add_tail(&led_cdev->trig_list, &trig->led_cdevs); > + > + /* Avoid the delayed blink path */ > + led_cdev->blink_delay_on = 0; > + led_cdev->blink_delay_off = 0; > + > + led_cdev->trigger = trig; > + if (trig->activate) > + trig->activate(led_cdev); > + break; > + } > +} > + > +static int led_trigger_panic_notifier(struct notifier_block *nb, > + unsigned long code, void *unused) > +{ > + struct led_classdev *led_cdev; > + > + list_for_each_entry(led_cdev, &leds_list, node) > + if (led_cdev->flags & LED_PANIC_INDICATOR) > + led_trigger_set_panic(led_cdev); > + return NOTIFY_DONE; > +} > + > +static struct notifier_block led_trigger_panic_nb = { > + .notifier_call = led_trigger_panic_notifier, > +}; > + > static long led_panic_blink(int state) > { > led_trigger_event(trigger, state ? LED_FULL : LED_OFF); > @@ -23,6 +67,9 @@ static long led_panic_blink(int state) > > static int __init ledtrig_panic_init(void) > { > + atomic_notifier_chain_register(&panic_notifier_list, > + &led_trigger_panic_nb); > + > led_trigger_register_simple("panic", &trigger); > panic_blink = led_panic_blink; > return 0; > diff --git a/include/linux/leds.h b/include/linux/leds.h > index 19eb10278bea..7e9fb00e15e8 100644 > --- a/include/linux/leds.h > +++ b/include/linux/leds.h > @@ -50,6 +50,7 @@ struct led_classdev { > #define LED_SYSFS_DISABLE (1 << 22) > #define LED_DEV_CAP_FLASH (1 << 23) > #define LED_HW_PLUGGABLE (1 << 24) > +#define LED_PANIC_INDICATOR (1 << 25) > > /* Set LED brightness level > * Must not sleep. Use brightness_set_blocking for drivers >
On 04/29/2016 09:20 AM, Jacek Anaszewski wrote: > Hi Ezequiel, > > Thanks for the update. It's indeed reasonable to have all the > switching infrastructure in ledtrig-panic.c. > > I've noticed two minor issues below. Since the merge window is imminent, I've addressed those issues by myself and applied the patch set to the for-next branch of linux-leds.git. Thanks, Jacek Anaszewski > On 04/29/2016 12:03 AM, Ezequiel Garcia wrote: >> This commit adds a new led_cdev flag LED_PANIC_INDICATOR, which >> allows to mark a specific LED to be switched to the "panic" >> trigger, on a kernel panic. >> >> This is useful to allow the user to assign a regular trigger >> to a given LED, and still blink that LED on a kernel panic. >> >> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> >> --- >> drivers/leds/led-triggers.c | 2 +- >> drivers/leds/leds.h | 1 + >> drivers/leds/trigger/Kconfig | 3 +++ >> drivers/leds/trigger/ledtrig-panic.c | 47 >> ++++++++++++++++++++++++++++++++++++ >> include/linux/leds.h | 1 + >> 5 files changed, 53 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c >> index 2181581795d3..55fa65e1ae03 100644 >> --- a/drivers/leds/led-triggers.c >> +++ b/drivers/leds/led-triggers.c >> @@ -26,7 +26,7 @@ >> * Nests outside led_cdev->trigger_lock >> */ >> static DECLARE_RWSEM(triggers_list_lock); >> -static LIST_HEAD(trigger_list); >> +LIST_HEAD(trigger_list); >> >> /* Used by LED Class */ >> >> diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h >> index db3f20da7221..7d38e6b9a740 100644 >> --- a/drivers/leds/leds.h >> +++ b/drivers/leds/leds.h >> @@ -30,5 +30,6 @@ void led_set_brightness_nosleep(struct led_classdev >> *led_cdev, >> >> extern struct rw_semaphore leds_list_lock; >> extern struct list_head leds_list; >> +extern struct list_head trigger_list; >> >> #endif /* __LEDS_H_INCLUDED */ >> diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig >> index beac8c31c51b..4e4521c9072a 100644 >> --- a/drivers/leds/trigger/Kconfig >> +++ b/drivers/leds/trigger/Kconfig >> @@ -121,6 +121,9 @@ config LEDS_TRIGGER_PANIC >> depends on LEDS_TRIGGERS >> help >> This allows LEDs to be configured to blink on a kernel panic. >> + Enabling this option will allow to mark certain LEDs as >> 'panic-indicators', > > s/"panic-indicators"/panic indicators/ > > I understand that you referred here to the DT property name, but this > is not obvious at first glance, and it is an implementation detail. > >> + allowing to blink them on a kernel panic, even if they are set to >> + a different trigger. >> If unsure, say Y. >> >> endif # LEDS_TRIGGERS >> diff --git a/drivers/leds/trigger/ b/drivers/leds/trigger/ledtrig-panic.c >> index 627b350c5ec3..3e447bd2064a 100644 >> --- a/drivers/leds/trigger/ledtrig-panic.c >> +++ b/drivers/leds/trigger/ledtrig-panic.c >> @@ -11,10 +11,54 @@ >> >> #include <linux/kernel.h> >> #include <linux/init.h> >> +#include <linux/notifier.h> >> #include <linux/leds.h> >> +#include "../leds.h" >> >> static struct led_trigger *trigger; >> >> +/* >> + * This is a called in a special context by the atomic panic > > s/is a/is/ > >> + * notifier. This means the trigger can be changed without >> + * worrying about locking. >> + */ >> +static void led_trigger_set_panic(struct led_classdev *led_cdev) >> +{ >> + struct led_trigger *trig; >> + >> + list_for_each_entry(trig, &trigger_list, next_trig) { >> + if (strcmp("panic", trig->name)) >> + continue; >> + if (led_cdev->trigger) >> + list_del(&led_cdev->trig_list); >> + list_add_tail(&led_cdev->trig_list, &trig->led_cdevs); >> + >> + /* Avoid the delayed blink path */ >> + led_cdev->blink_delay_on = 0; >> + led_cdev->blink_delay_off = 0; >> + >> + led_cdev->trigger = trig; >> + if (trig->activate) >> + trig->activate(led_cdev); >> + break; >> + } >> +} >> + >> +static int led_trigger_panic_notifier(struct notifier_block *nb, >> + unsigned long code, void *unused) >> +{ >> + struct led_classdev *led_cdev; >> + >> + list_for_each_entry(led_cdev, &leds_list, node) >> + if (led_cdev->flags & LED_PANIC_INDICATOR) >> + led_trigger_set_panic(led_cdev); >> + return NOTIFY_DONE; >> +} >> + >> +static struct notifier_block led_trigger_panic_nb = { >> + .notifier_call = led_trigger_panic_notifier, >> +}; >> + >> static long led_panic_blink(int state) >> { >> led_trigger_event(trigger, state ? LED_FULL : LED_OFF); >> @@ -23,6 +67,9 @@ static long led_panic_blink(int state) >> >> static int __init ledtrig_panic_init(void) >> { >> + atomic_notifier_chain_register(&panic_notifier_list, >> + &led_trigger_panic_nb); >> + >> led_trigger_register_simple("panic", &trigger); >> panic_blink = led_panic_blink; >> return 0; >> diff --git a/include/linux/leds.h b/include/linux/leds.h >> index 19eb10278bea..7e9fb00e15e8 100644 >> --- a/include/linux/leds.h >> +++ b/include/linux/leds.h >> @@ -50,6 +50,7 @@ struct led_classdev { >> #define LED_SYSFS_DISABLE (1 << 22) >> #define LED_DEV_CAP_FLASH (1 << 23) >> #define LED_HW_PLUGGABLE (1 << 24) >> +#define LED_PANIC_INDICATOR (1 << 25) >> >> /* Set LED brightness level >> * Must not sleep. Use brightness_set_blocking for drivers >> >
On 6 May 2016 at 06:03, Jacek Anaszewski <j.anaszewski@samsung.com> wrote: > On 04/29/2016 09:20 AM, Jacek Anaszewski wrote: >> >> Hi Ezequiel, >> >> Thanks for the update. It's indeed reasonable to have all the >> switching infrastructure in ledtrig-panic.c. >> >> I've noticed two minor issues below. > > > Since the merge window is imminent, I've addressed those issues by > myself and applied the patch set to the for-next branch > of linux-leds.git. > Thanks a lot for taking care of this, Jacek!
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c index 2181581795d3..55fa65e1ae03 100644 --- a/drivers/leds/led-triggers.c +++ b/drivers/leds/led-triggers.c @@ -26,7 +26,7 @@ * Nests outside led_cdev->trigger_lock */ static DECLARE_RWSEM(triggers_list_lock); -static LIST_HEAD(trigger_list); +LIST_HEAD(trigger_list); /* Used by LED Class */ diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h index db3f20da7221..7d38e6b9a740 100644 --- a/drivers/leds/leds.h +++ b/drivers/leds/leds.h @@ -30,5 +30,6 @@ void led_set_brightness_nosleep(struct led_classdev *led_cdev, extern struct rw_semaphore leds_list_lock; extern struct list_head leds_list; +extern struct list_head trigger_list; #endif /* __LEDS_H_INCLUDED */ diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig index beac8c31c51b..4e4521c9072a 100644 --- a/drivers/leds/trigger/Kconfig +++ b/drivers/leds/trigger/Kconfig @@ -121,6 +121,9 @@ config LEDS_TRIGGER_PANIC depends on LEDS_TRIGGERS help This allows LEDs to be configured to blink on a kernel panic. + Enabling this option will allow to mark certain LEDs as 'panic-indicators', + allowing to blink them on a kernel panic, even if they are set to + a different trigger. If unsure, say Y. endif # LEDS_TRIGGERS diff --git a/drivers/leds/trigger/ledtrig-panic.c b/drivers/leds/trigger/ledtrig-panic.c index 627b350c5ec3..3e447bd2064a 100644 --- a/drivers/leds/trigger/ledtrig-panic.c +++ b/drivers/leds/trigger/ledtrig-panic.c @@ -11,10 +11,54 @@ #include <linux/kernel.h> #include <linux/init.h> +#include <linux/notifier.h> #include <linux/leds.h> +#include "../leds.h" static struct led_trigger *trigger; +/* + * This is a called in a special context by the atomic panic + * notifier. This means the trigger can be changed without + * worrying about locking. + */ +static void led_trigger_set_panic(struct led_classdev *led_cdev) +{ + struct led_trigger *trig; + + list_for_each_entry(trig, &trigger_list, next_trig) { + if (strcmp("panic", trig->name)) + continue; + if (led_cdev->trigger) + list_del(&led_cdev->trig_list); + list_add_tail(&led_cdev->trig_list, &trig->led_cdevs); + + /* Avoid the delayed blink path */ + led_cdev->blink_delay_on = 0; + led_cdev->blink_delay_off = 0; + + led_cdev->trigger = trig; + if (trig->activate) + trig->activate(led_cdev); + break; + } +} + +static int led_trigger_panic_notifier(struct notifier_block *nb, + unsigned long code, void *unused) +{ + struct led_classdev *led_cdev; + + list_for_each_entry(led_cdev, &leds_list, node) + if (led_cdev->flags & LED_PANIC_INDICATOR) + led_trigger_set_panic(led_cdev); + return NOTIFY_DONE; +} + +static struct notifier_block led_trigger_panic_nb = { + .notifier_call = led_trigger_panic_notifier, +}; + static long led_panic_blink(int state) { led_trigger_event(trigger, state ? LED_FULL : LED_OFF); @@ -23,6 +67,9 @@ static long led_panic_blink(int state) static int __init ledtrig_panic_init(void) { + atomic_notifier_chain_register(&panic_notifier_list, + &led_trigger_panic_nb); + led_trigger_register_simple("panic", &trigger); panic_blink = led_panic_blink; return 0; diff --git a/include/linux/leds.h b/include/linux/leds.h index 19eb10278bea..7e9fb00e15e8 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -50,6 +50,7 @@ struct led_classdev { #define LED_SYSFS_DISABLE (1 << 22) #define LED_DEV_CAP_FLASH (1 << 23) #define LED_HW_PLUGGABLE (1 << 24) +#define LED_PANIC_INDICATOR (1 << 25) /* Set LED brightness level * Must not sleep. Use brightness_set_blocking for drivers
This commit adds a new led_cdev flag LED_PANIC_INDICATOR, which allows to mark a specific LED to be switched to the "panic" trigger, on a kernel panic. This is useful to allow the user to assign a regular trigger to a given LED, and still blink that LED on a kernel panic. Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> --- drivers/leds/led-triggers.c | 2 +- drivers/leds/leds.h | 1 + drivers/leds/trigger/Kconfig | 3 +++ drivers/leds/trigger/ledtrig-panic.c | 47 ++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 1 + 5 files changed, 53 insertions(+), 1 deletion(-)