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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2021-10-13 11:37:19 +0200 |
|---|---|---|
| committer | Pavel Machek <pavel@ucw.cz> | 2021-10-13 20:07:57 +0200 |
| commit | 97b31c1f8eb865bc3aa5f4a08286a6406d782ea8 (patch) | |
| tree | 8e091f2c560334b4b176b133c4fdea5c443b90dd /drivers/leds | |
| parent | leds: trigger: use RCU to protect the led_cdevs list (diff) | |
| download | linux-97b31c1f8eb865bc3aa5f4a08286a6406d782ea8.tar.xz linux-97b31c1f8eb865bc3aa5f4a08286a6406d782ea8.zip | |
leds: trigger: Disable CPU trigger on PREEMPT_RT
The CPU trigger is invoked on ARM from CPU-idle. That trigger later
invokes led_trigger_event() which may invoke the callback of the actual driver.
That driver can acquire a spinlock_t which is okay on kernel without
PREEMPT_RT. On a PREEMPT_RT enabled kernel this lock is turned into a
sleeping lock and must not be acquired with disabled interrupts.
Disable the CPU trigger on PREEMPT_RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lkml.kernel.org/r/20210924111501.m57cwwn7ahiyxxdd@linutronix.de
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/trigger/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig index 1f1d57288085..dc6816d36d06 100644 --- a/drivers/leds/trigger/Kconfig +++ b/drivers/leds/trigger/Kconfig @@ -64,6 +64,7 @@ config LEDS_TRIGGER_BACKLIGHT config LEDS_TRIGGER_CPU bool "LED CPU Trigger" + depends on !PREEMPT_RT help This allows LEDs to be controlled by active CPUs. This shows the active CPUs across an array of LEDs so you can see which |