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authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2021-10-13 12:37:19 +0300
committerPavel Machek <pavel@ucw.cz>2021-10-13 21:07:57 +0300
commit97b31c1f8eb865bc3aa5f4a08286a6406d782ea8 (patch)
tree8e091f2c560334b4b176b133c4fdea5c443b90dd /drivers/leds/trigger
parent2a5a8fa8b23144d14567d6f8293dd6fbeecee393 (diff)
downloadlinux-97b31c1f8eb865bc3aa5f4a08286a6406d782ea8.tar.xz
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/trigger')
-rw-r--r--drivers/leds/trigger/Kconfig1
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