PM: sleep: Add pm_debug_messages kernel command line option (db96a759) · Commits · 戴 / test

Debug messages from the system suspend/hibernation infrastructure are disabled by default, and can only be enabled after the system has boot up via /sys/power/pm_debug_messages. This makes the hibernation resume hard to track as it involves system boot up across hibernation. There's no chance for software_resume() to track the resume process, for example. Add a kernel command line option to set pm_debug_messages during boot up. Signed-off-by:

Chen Yu <yu.c.chen@intel.com> [ rjw: Subject & changelog ] Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Documentation/admin-guide/kernel-parameters.txt

+3 −0

Original line number	Diff line number	Diff line
		@@ -3719,6 +3719,9 @@
		Override pmtimer IOPort with a hex value.
		e.g. pmtmr=0x508

		pm_debug_messages [SUSPEND,KNL]
		Enable suspend/resume debug messages during boot up.

		pnp.debug=1 [PNP]
		Enable PNP debug messages (depends on the
		CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time

kernel/power/main.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -535,6 +535,13 @@ static ssize_t pm_debug_messages_store(struct kobject *kobj,

		power_attr(pm_debug_messages);

		static int __init pm_debug_messages_setup(char *str)
		{
		pm_debug_messages_on = true;
		return 1;
		}
		__setup("pm_debug_messages", pm_debug_messages_setup);

		/**
		* __pm_pr_dbg - Print a suspend debug message to the kernel log.
		* @defer: Whether or not to use printk_deferred() to print the message.

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