From 3257f8b06ba22a903b51ff2c39b39949c7b04cb7 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 23 Jan 2014 14:45:59 +0100 Subject: [PATCH 132/158] 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 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 --- drivers/leds/trigger/Kconfig | 1 + 1 file changed, 1 insertion(+) Index: linux-5.15.19-rt29/drivers/leds/trigger/Kconfig =================================================================== --- linux-5.15.19-rt29.orig/drivers/leds/trigger/Kconfig +++ linux-5.15.19-rt29/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