Commit a67818f7 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Rafael J. Wysocki
Browse files

PM: dpm_watchdog: add module param to backtrace all CPUs 



Add dpm_watchdog_all_cpu_backtrace module parameter which
controls all CPU backtrace dump before the DPM watchdog panics
the system.

This is expected to help understand what might have caused device
timeout.

Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: default avatarTomasz Figa <tfiga@chromium.org>
Reviewed-by: default avatarDhruva Gole <d-gole@ti.com>
Link: https://patch.msgid.link/20251007063551.3147937-1-senozhatsky@chromium.org


[ rjw: Subject and changelog edits ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 5a151c23

drivers/base/power/main.c

+10 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/cpufreq.h>

#include <linux/devfreq.h>

#include <linux/timer.h>

#include <linux/nmi.h>



#include "../base.h"

#include "power.h"
@@ -515,6 +516,11 @@ struct dpm_watchdog { 
#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \

	struct dpm_watchdog wd



static bool __read_mostly dpm_watchdog_all_cpu_backtrace;

module_param(dpm_watchdog_all_cpu_backtrace, bool, 0644);

MODULE_PARM_DESC(dpm_watchdog_all_cpu_backtrace,

		 "Backtrace all CPUs on DPM watchdog timeout");



/**

 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.

 * @t: The timer that PM watchdog depends on.
@@ -530,8 +536,12 @@ static void dpm_watchdog_handler(struct timer_list *t) 
	unsigned int time_left;



	if (wd->fatal) {

		unsigned int this_cpu = smp_processor_id();



		dev_emerg(wd->dev, "**** DPM device timeout ****\n");

		show_stack(wd->tsk, NULL, KERN_EMERG);

		if (dpm_watchdog_all_cpu_backtrace)

			trigger_allbutcpu_cpu_backtrace(this_cpu);

		panic("%s %s: unrecoverable failure\n",

			dev_driver_string(wd->dev), dev_name(wd->dev));

	}