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| author | Nathan Lynch <ntl@pobox.com> | 2012-11-05 06:20:31 -0800 |
|---|---|---|
| committer | Bryan Wu <roc@roc-samos.(none)> | 2012-11-11 12:09:43 -0800 |
| commit | 0b8728d6f140dc20690384286ade47c956edc999 (patch) | |
| tree | 52a1c8a4e0b3b39396f2967e8478acf9464ca0c5 /drivers/leds | |
| parent | 77b67063bb6bce6d475e910d3b886a606d0d91f7 (diff) | |
| download | linux-0b8728d6f140dc20690384286ade47c956edc999.tar.gz linux-0b8728d6f140dc20690384286ade47c956edc999.tar.bz2 linux-0b8728d6f140dc20690384286ade47c956edc999.zip | |
ledtrig-cpu: kill useless mutex to fix sleep in atomic context
Seeing the following every time the CPU enters or leaves idle on a
Beagleboard:
BUG: sleeping function called from invalid context at kernel/mutex.c:269
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0
no locks held by swapper/0/0.
[<c001659c>] (unwind_backtrace+0x0/0xf8) from [<c05aaa7c>] (mutex_lock_nested+0x24/0x380)
[<c05aaa7c>] (mutex_lock_nested+0x24/0x380) from [<c043bd1c>] (ledtrig_cpu+0x38/0x88)
[<c043bd1c>] (ledtrig_cpu+0x38/0x88) from [<c000f4b0>] (cpu_idle+0xf4/0x120)
[<c000f4b0>] (cpu_idle+0xf4/0x120) from [<c07e47c8>] (start_kernel+0x2bc/0x30c)
Miles Lane has reported seeing similar splats during system suspend.
The mutex in struct led_trigger_cpu appears to have no function: it
resides in a per-cpu data structure which never changes after the
trigger is registered. So just remove it.
Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Bryan Wu <roc@roc-samos.(none)>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/ledtrig-cpu.c | 21 |
1 files changed, 0 insertions, 21 deletions
diff --git a/drivers/leds/ledtrig-cpu.c b/drivers/leds/ledtrig-cpu.c index b312056da14d..4239b3955ff0 100644 --- a/drivers/leds/ledtrig-cpu.c +++ b/drivers/leds/ledtrig-cpu.c @@ -33,8 +33,6 @@ struct led_trigger_cpu { char name[MAX_NAME_LEN]; struct led_trigger *_trig; - struct mutex lock; - int lock_is_inited; }; static DEFINE_PER_CPU(struct led_trigger_cpu, cpu_trig); @@ -50,12 +48,6 @@ void ledtrig_cpu(enum cpu_led_event ledevt) { struct led_trigger_cpu *trig = &__get_cpu_var(cpu_trig); - /* mutex lock should be initialized before calling mutex_call() */ - if (!trig->lock_is_inited) - return; - - mutex_lock(&trig->lock); - /* Locate the correct CPU LED */ switch (ledevt) { case CPU_LED_IDLE_END: @@ -75,8 +67,6 @@ void ledtrig_cpu(enum cpu_led_event ledevt) /* Will leave the LED as it is */ break; } - - mutex_unlock(&trig->lock); } EXPORT_SYMBOL(ledtrig_cpu); @@ -117,14 +107,9 @@ static int __init ledtrig_cpu_init(void) for_each_possible_cpu(cpu) { struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu); - mutex_init(&trig->lock); - snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu); - mutex_lock(&trig->lock); led_trigger_register_simple(trig->name, &trig->_trig); - trig->lock_is_inited = 1; - mutex_unlock(&trig->lock); } register_syscore_ops(&ledtrig_cpu_syscore_ops); @@ -142,15 +127,9 @@ static void __exit ledtrig_cpu_exit(void) for_each_possible_cpu(cpu) { struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu); - mutex_lock(&trig->lock); - led_trigger_unregister_simple(trig->_trig); trig->_trig = NULL; memset(trig->name, 0, MAX_NAME_LEN); - trig->lock_is_inited = 0; - - mutex_unlock(&trig->lock); - mutex_destroy(&trig->lock); } unregister_syscore_ops(&ledtrig_cpu_syscore_ops); |