linux/drivers/leds/trigger/ledtrig-heartbeat.c

214 lines
5.4 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-only
/*
* LED Heartbeat Trigger
*
* Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
*
* Based on Richard Purdie's ledtrig-timer.c and some arch's
* CONFIG_HEARTBEAT code.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
kernel.h: split out panic and oops helpers kernel.h is being used as a dump for all kinds of stuff for a long time. Here is the attempt to start cleaning it up by splitting out panic and oops helpers. There are several purposes of doing this: - dropping dependency in bug.h - dropping a loop by moving out panic_notifier.h - unload kernel.h from something which has its own domain At the same time convert users tree-wide to use new headers, although for the time being include new header back to kernel.h to avoid twisted indirected includes for existing users. [akpm@linux-foundation.org: thread_info.h needs limits.h] [andriy.shevchenko@linux.intel.com: ia64 fix] Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Co-developed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Sebastian Reichel <sre@kernel.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Acked-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 04:54:59 +03:00
#include <linux/panic_notifier.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 11:04:11 +03:00
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/leds.h>
#include <linux/reboot.h>
#include "../leds.h"
leds: heartbeat: fix bug on panic With commit 49dca5aebfdeadd4bf27b6cb4c60392147dc35a4 I introduced a bug (visible if CONFIG_PROVE_RCU is enabled) which occures when a panic has happened: [ 1526.520230] =============================== [ 1526.520230] [ INFO: suspicious RCU usage. ] [ 1526.520230] 3.5.0-rc1+ #12 Not tainted [ 1526.520230] ------------------------------- [ 1526.520230] /c/kernel-tests/mm/include/linux/rcupdate.h:436 Illegal context switch in RCU read-side critical section! [ 1526.520230] [ 1526.520230] other info that might help us debug this: [ 1526.520230] [ 1526.520230] [ 1526.520230] rcu_scheduler_active = 1, debug_locks = 0 [ 1526.520230] 3 locks held by net.agent/3279: [ 1526.520230] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff82f85962>] do_page_fault+0x193/0x390 [ 1526.520230] #1: (panic_lock){+.+...}, at: [<ffffffff82ed2830>] panic+0x37/0x1d3 [ 1526.520230] #2: (rcu_read_lock){.+.+..}, at: [<ffffffff810b9b28>] rcu_lock_acquire+0x0/0x29 [ 1526.520230] [ 1526.520230] stack backtrace: [ 1526.520230] Pid: 3279, comm: net.agent Not tainted 3.5.0-rc1+ #12 [ 1526.520230] Call Trace: [ 1526.520230] [<ffffffff810e1570>] lockdep_rcu_suspicious+0x109/0x112 [ 1526.520230] [<ffffffff810bfe3a>] rcu_preempt_sleep_check+0x45/0x47 [ 1526.520230] [<ffffffff810bfe5a>] __might_sleep+0x1e/0x19a [ 1526.520230] [<ffffffff82f8010e>] down_write+0x26/0x81 [ 1526.520230] [<ffffffff8276a966>] led_trigger_unregister+0x1f/0x9c [ 1526.520230] [<ffffffff8276def5>] heartbeat_reboot_notifier+0x15/0x19 [ 1526.520230] [<ffffffff82f85bf5>] notifier_call_chain+0x96/0xcd [ 1526.520230] [<ffffffff82f85cba>] __atomic_notifier_call_chain+0x8e/0xff [ 1526.520230] [<ffffffff81094b7c>] ? kmsg_dump+0x37/0x1eb [ 1526.520230] [<ffffffff82f85d3f>] atomic_notifier_call_chain+0x14/0x16 [ 1526.520230] [<ffffffff82ed28e1>] panic+0xe8/0x1d3 [ 1526.520230] [<ffffffff811473e2>] out_of_memory+0x15d/0x1d3 So in case of a panic, now just turn of the LED. Other approaches like scheduling a work to unregister the trigger aren't working because there isn't much which still runs after a panic occured (except timers). Signed-off-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-07-03 10:35:47 +04:00
static int panic_heartbeats;
struct heartbeat_trig_data {
struct led_classdev *led_cdev;
unsigned int phase;
unsigned int period;
struct timer_list timer;
unsigned int invert;
};
static void led_heartbeat_function(struct timer_list *t)
{
struct heartbeat_trig_data *heartbeat_data =
from_timer(heartbeat_data, t, timer);
struct led_classdev *led_cdev;
unsigned long brightness = LED_OFF;
unsigned long delay = 0;
led_cdev = heartbeat_data->led_cdev;
leds: heartbeat: fix bug on panic With commit 49dca5aebfdeadd4bf27b6cb4c60392147dc35a4 I introduced a bug (visible if CONFIG_PROVE_RCU is enabled) which occures when a panic has happened: [ 1526.520230] =============================== [ 1526.520230] [ INFO: suspicious RCU usage. ] [ 1526.520230] 3.5.0-rc1+ #12 Not tainted [ 1526.520230] ------------------------------- [ 1526.520230] /c/kernel-tests/mm/include/linux/rcupdate.h:436 Illegal context switch in RCU read-side critical section! [ 1526.520230] [ 1526.520230] other info that might help us debug this: [ 1526.520230] [ 1526.520230] [ 1526.520230] rcu_scheduler_active = 1, debug_locks = 0 [ 1526.520230] 3 locks held by net.agent/3279: [ 1526.520230] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff82f85962>] do_page_fault+0x193/0x390 [ 1526.520230] #1: (panic_lock){+.+...}, at: [<ffffffff82ed2830>] panic+0x37/0x1d3 [ 1526.520230] #2: (rcu_read_lock){.+.+..}, at: [<ffffffff810b9b28>] rcu_lock_acquire+0x0/0x29 [ 1526.520230] [ 1526.520230] stack backtrace: [ 1526.520230] Pid: 3279, comm: net.agent Not tainted 3.5.0-rc1+ #12 [ 1526.520230] Call Trace: [ 1526.520230] [<ffffffff810e1570>] lockdep_rcu_suspicious+0x109/0x112 [ 1526.520230] [<ffffffff810bfe3a>] rcu_preempt_sleep_check+0x45/0x47 [ 1526.520230] [<ffffffff810bfe5a>] __might_sleep+0x1e/0x19a [ 1526.520230] [<ffffffff82f8010e>] down_write+0x26/0x81 [ 1526.520230] [<ffffffff8276a966>] led_trigger_unregister+0x1f/0x9c [ 1526.520230] [<ffffffff8276def5>] heartbeat_reboot_notifier+0x15/0x19 [ 1526.520230] [<ffffffff82f85bf5>] notifier_call_chain+0x96/0xcd [ 1526.520230] [<ffffffff82f85cba>] __atomic_notifier_call_chain+0x8e/0xff [ 1526.520230] [<ffffffff81094b7c>] ? kmsg_dump+0x37/0x1eb [ 1526.520230] [<ffffffff82f85d3f>] atomic_notifier_call_chain+0x14/0x16 [ 1526.520230] [<ffffffff82ed28e1>] panic+0xe8/0x1d3 [ 1526.520230] [<ffffffff811473e2>] out_of_memory+0x15d/0x1d3 So in case of a panic, now just turn of the LED. Other approaches like scheduling a work to unregister the trigger aren't working because there isn't much which still runs after a panic occured (except timers). Signed-off-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-07-03 10:35:47 +04:00
if (unlikely(panic_heartbeats)) {
led_set_brightness_nosleep(led_cdev, LED_OFF);
leds: heartbeat: fix bug on panic With commit 49dca5aebfdeadd4bf27b6cb4c60392147dc35a4 I introduced a bug (visible if CONFIG_PROVE_RCU is enabled) which occures when a panic has happened: [ 1526.520230] =============================== [ 1526.520230] [ INFO: suspicious RCU usage. ] [ 1526.520230] 3.5.0-rc1+ #12 Not tainted [ 1526.520230] ------------------------------- [ 1526.520230] /c/kernel-tests/mm/include/linux/rcupdate.h:436 Illegal context switch in RCU read-side critical section! [ 1526.520230] [ 1526.520230] other info that might help us debug this: [ 1526.520230] [ 1526.520230] [ 1526.520230] rcu_scheduler_active = 1, debug_locks = 0 [ 1526.520230] 3 locks held by net.agent/3279: [ 1526.520230] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff82f85962>] do_page_fault+0x193/0x390 [ 1526.520230] #1: (panic_lock){+.+...}, at: [<ffffffff82ed2830>] panic+0x37/0x1d3 [ 1526.520230] #2: (rcu_read_lock){.+.+..}, at: [<ffffffff810b9b28>] rcu_lock_acquire+0x0/0x29 [ 1526.520230] [ 1526.520230] stack backtrace: [ 1526.520230] Pid: 3279, comm: net.agent Not tainted 3.5.0-rc1+ #12 [ 1526.520230] Call Trace: [ 1526.520230] [<ffffffff810e1570>] lockdep_rcu_suspicious+0x109/0x112 [ 1526.520230] [<ffffffff810bfe3a>] rcu_preempt_sleep_check+0x45/0x47 [ 1526.520230] [<ffffffff810bfe5a>] __might_sleep+0x1e/0x19a [ 1526.520230] [<ffffffff82f8010e>] down_write+0x26/0x81 [ 1526.520230] [<ffffffff8276a966>] led_trigger_unregister+0x1f/0x9c [ 1526.520230] [<ffffffff8276def5>] heartbeat_reboot_notifier+0x15/0x19 [ 1526.520230] [<ffffffff82f85bf5>] notifier_call_chain+0x96/0xcd [ 1526.520230] [<ffffffff82f85cba>] __atomic_notifier_call_chain+0x8e/0xff [ 1526.520230] [<ffffffff81094b7c>] ? kmsg_dump+0x37/0x1eb [ 1526.520230] [<ffffffff82f85d3f>] atomic_notifier_call_chain+0x14/0x16 [ 1526.520230] [<ffffffff82ed28e1>] panic+0xe8/0x1d3 [ 1526.520230] [<ffffffff811473e2>] out_of_memory+0x15d/0x1d3 So in case of a panic, now just turn of the LED. Other approaches like scheduling a work to unregister the trigger aren't working because there isn't much which still runs after a panic occured (except timers). Signed-off-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-07-03 10:35:47 +04:00
return;
}
if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags))
led_cdev->blink_brightness = led_cdev->new_blink_brightness;
/* acts like an actual heart beat -- ie thump-thump-pause... */
switch (heartbeat_data->phase) {
case 0:
/*
* The hyperbolic function below modifies the
* heartbeat period length in dependency of the
* current (1min) load. It goes through the points
* f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
*/
heartbeat_data->period = 300 +
(6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
heartbeat_data->period =
msecs_to_jiffies(heartbeat_data->period);
delay = msecs_to_jiffies(70);
heartbeat_data->phase++;
if (!heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
case 1:
delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
heartbeat_data->phase++;
if (heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
case 2:
delay = msecs_to_jiffies(70);
heartbeat_data->phase++;
if (!heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
default:
delay = heartbeat_data->period - heartbeat_data->period / 4 -
msecs_to_jiffies(70);
heartbeat_data->phase = 0;
if (heartbeat_data->invert)
brightness = led_cdev->blink_brightness;
break;
}
led_set_brightness_nosleep(led_cdev, brightness);
mod_timer(&heartbeat_data->timer, jiffies + delay);
}
static ssize_t led_invert_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct heartbeat_trig_data *heartbeat_data =
led_trigger_get_drvdata(dev);
return sprintf(buf, "%u\n", heartbeat_data->invert);
}
static ssize_t led_invert_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t size)
{
struct heartbeat_trig_data *heartbeat_data =
led_trigger_get_drvdata(dev);
unsigned long state;
int ret;
ret = kstrtoul(buf, 0, &state);
if (ret)
return ret;
heartbeat_data->invert = !!state;
return size;
}
static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
static struct attribute *heartbeat_trig_attrs[] = {
&dev_attr_invert.attr,
NULL
};
ATTRIBUTE_GROUPS(heartbeat_trig);
static int heartbeat_trig_activate(struct led_classdev *led_cdev)
{
struct heartbeat_trig_data *heartbeat_data;
heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
if (!heartbeat_data)
return -ENOMEM;
led_set_trigger_data(led_cdev, heartbeat_data);
heartbeat_data->led_cdev = led_cdev;
timer_setup(&heartbeat_data->timer, led_heartbeat_function, 0);
heartbeat_data->phase = 0;
if (!led_cdev->blink_brightness)
led_cdev->blink_brightness = led_cdev->max_brightness;
led_heartbeat_function(&heartbeat_data->timer);
set_bit(LED_BLINK_SW, &led_cdev->work_flags);
return 0;
}
static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
{
struct heartbeat_trig_data *heartbeat_data =
led_get_trigger_data(led_cdev);
timer_shutdown_sync(&heartbeat_data->timer);
kfree(heartbeat_data);
clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
}
static struct led_trigger heartbeat_led_trigger = {
.name = "heartbeat",
.activate = heartbeat_trig_activate,
.deactivate = heartbeat_trig_deactivate,
.groups = heartbeat_trig_groups,
};
static int heartbeat_reboot_notifier(struct notifier_block *nb,
unsigned long code, void *unused)
{
led_trigger_unregister(&heartbeat_led_trigger);
return NOTIFY_DONE;
}
leds: heartbeat: fix bug on panic With commit 49dca5aebfdeadd4bf27b6cb4c60392147dc35a4 I introduced a bug (visible if CONFIG_PROVE_RCU is enabled) which occures when a panic has happened: [ 1526.520230] =============================== [ 1526.520230] [ INFO: suspicious RCU usage. ] [ 1526.520230] 3.5.0-rc1+ #12 Not tainted [ 1526.520230] ------------------------------- [ 1526.520230] /c/kernel-tests/mm/include/linux/rcupdate.h:436 Illegal context switch in RCU read-side critical section! [ 1526.520230] [ 1526.520230] other info that might help us debug this: [ 1526.520230] [ 1526.520230] [ 1526.520230] rcu_scheduler_active = 1, debug_locks = 0 [ 1526.520230] 3 locks held by net.agent/3279: [ 1526.520230] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff82f85962>] do_page_fault+0x193/0x390 [ 1526.520230] #1: (panic_lock){+.+...}, at: [<ffffffff82ed2830>] panic+0x37/0x1d3 [ 1526.520230] #2: (rcu_read_lock){.+.+..}, at: [<ffffffff810b9b28>] rcu_lock_acquire+0x0/0x29 [ 1526.520230] [ 1526.520230] stack backtrace: [ 1526.520230] Pid: 3279, comm: net.agent Not tainted 3.5.0-rc1+ #12 [ 1526.520230] Call Trace: [ 1526.520230] [<ffffffff810e1570>] lockdep_rcu_suspicious+0x109/0x112 [ 1526.520230] [<ffffffff810bfe3a>] rcu_preempt_sleep_check+0x45/0x47 [ 1526.520230] [<ffffffff810bfe5a>] __might_sleep+0x1e/0x19a [ 1526.520230] [<ffffffff82f8010e>] down_write+0x26/0x81 [ 1526.520230] [<ffffffff8276a966>] led_trigger_unregister+0x1f/0x9c [ 1526.520230] [<ffffffff8276def5>] heartbeat_reboot_notifier+0x15/0x19 [ 1526.520230] [<ffffffff82f85bf5>] notifier_call_chain+0x96/0xcd [ 1526.520230] [<ffffffff82f85cba>] __atomic_notifier_call_chain+0x8e/0xff [ 1526.520230] [<ffffffff81094b7c>] ? kmsg_dump+0x37/0x1eb [ 1526.520230] [<ffffffff82f85d3f>] atomic_notifier_call_chain+0x14/0x16 [ 1526.520230] [<ffffffff82ed28e1>] panic+0xe8/0x1d3 [ 1526.520230] [<ffffffff811473e2>] out_of_memory+0x15d/0x1d3 So in case of a panic, now just turn of the LED. Other approaches like scheduling a work to unregister the trigger aren't working because there isn't much which still runs after a panic occured (except timers). Signed-off-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-07-03 10:35:47 +04:00
static int heartbeat_panic_notifier(struct notifier_block *nb,
unsigned long code, void *unused)
{
panic_heartbeats = 1;
return NOTIFY_DONE;
}
static struct notifier_block heartbeat_reboot_nb = {
.notifier_call = heartbeat_reboot_notifier,
};
static struct notifier_block heartbeat_panic_nb = {
leds: heartbeat: fix bug on panic With commit 49dca5aebfdeadd4bf27b6cb4c60392147dc35a4 I introduced a bug (visible if CONFIG_PROVE_RCU is enabled) which occures when a panic has happened: [ 1526.520230] =============================== [ 1526.520230] [ INFO: suspicious RCU usage. ] [ 1526.520230] 3.5.0-rc1+ #12 Not tainted [ 1526.520230] ------------------------------- [ 1526.520230] /c/kernel-tests/mm/include/linux/rcupdate.h:436 Illegal context switch in RCU read-side critical section! [ 1526.520230] [ 1526.520230] other info that might help us debug this: [ 1526.520230] [ 1526.520230] [ 1526.520230] rcu_scheduler_active = 1, debug_locks = 0 [ 1526.520230] 3 locks held by net.agent/3279: [ 1526.520230] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff82f85962>] do_page_fault+0x193/0x390 [ 1526.520230] #1: (panic_lock){+.+...}, at: [<ffffffff82ed2830>] panic+0x37/0x1d3 [ 1526.520230] #2: (rcu_read_lock){.+.+..}, at: [<ffffffff810b9b28>] rcu_lock_acquire+0x0/0x29 [ 1526.520230] [ 1526.520230] stack backtrace: [ 1526.520230] Pid: 3279, comm: net.agent Not tainted 3.5.0-rc1+ #12 [ 1526.520230] Call Trace: [ 1526.520230] [<ffffffff810e1570>] lockdep_rcu_suspicious+0x109/0x112 [ 1526.520230] [<ffffffff810bfe3a>] rcu_preempt_sleep_check+0x45/0x47 [ 1526.520230] [<ffffffff810bfe5a>] __might_sleep+0x1e/0x19a [ 1526.520230] [<ffffffff82f8010e>] down_write+0x26/0x81 [ 1526.520230] [<ffffffff8276a966>] led_trigger_unregister+0x1f/0x9c [ 1526.520230] [<ffffffff8276def5>] heartbeat_reboot_notifier+0x15/0x19 [ 1526.520230] [<ffffffff82f85bf5>] notifier_call_chain+0x96/0xcd [ 1526.520230] [<ffffffff82f85cba>] __atomic_notifier_call_chain+0x8e/0xff [ 1526.520230] [<ffffffff81094b7c>] ? kmsg_dump+0x37/0x1eb [ 1526.520230] [<ffffffff82f85d3f>] atomic_notifier_call_chain+0x14/0x16 [ 1526.520230] [<ffffffff82ed28e1>] panic+0xe8/0x1d3 [ 1526.520230] [<ffffffff811473e2>] out_of_memory+0x15d/0x1d3 So in case of a panic, now just turn of the LED. Other approaches like scheduling a work to unregister the trigger aren't working because there isn't much which still runs after a panic occured (except timers). Signed-off-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-07-03 10:35:47 +04:00
.notifier_call = heartbeat_panic_notifier,
};
static int __init heartbeat_trig_init(void)
{
int rc = led_trigger_register(&heartbeat_led_trigger);
if (!rc) {
atomic_notifier_chain_register(&panic_notifier_list,
&heartbeat_panic_nb);
register_reboot_notifier(&heartbeat_reboot_nb);
}
return rc;
}
static void __exit heartbeat_trig_exit(void)
{
unregister_reboot_notifier(&heartbeat_reboot_nb);
atomic_notifier_chain_unregister(&panic_notifier_list,
&heartbeat_panic_nb);
led_trigger_unregister(&heartbeat_led_trigger);
}
module_init(heartbeat_trig_init);
module_exit(heartbeat_trig_exit);
MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_DESCRIPTION("Heartbeat LED trigger");
MODULE_LICENSE("GPL v2");