From 3257f8b06ba22a903b51ff2c39b39949c7b04cb7 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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 <bigeasy@linutronix.de>
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/drivers/leds/trigger/Kconfig:67 @ 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