From 97b31c1f8eb865bc3aa5f4a08286a6406d782ea8 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 13 Oct 2021 11:37:19 +0200 Subject: [PATCH] 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 Link: https://lkml.kernel.org/r/20210924111501.m57cwwn7ahiyxxdd@linutronix.de Signed-off-by: Pavel Machek --- drivers/leds/trigger/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig index 1f1d572..dc6816d 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 -- 2.7.4