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| author | Chen Yu <yu.c.chen@intel.com> | 2020-04-02 09:56:52 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-04-02 15:29:56 +0200 |
| commit | db96a75946d3a2a41092c83992e65f727cd35529 (patch) | |
| tree | 78ed92834bbd1aea7e3d272af8d3cb44c50bf237 | |
| parent | PM: sleep: core: Drop racy and redundant checks from device_prepare() (diff) | |
| download | linux-db96a75946d3a2a41092c83992e65f727cd35529.tar.xz linux-db96a75946d3a2a41092c83992e65f727cd35529.zip | |
PM: sleep: Add pm_debug_messages kernel command line option
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>
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 3 | ||||
| -rw-r--r-- | kernel/power/main.c | 7 |
2 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 4e3885e38179..df2c2b97f417 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -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 diff --git a/kernel/power/main.c b/kernel/power/main.c index 69b7a8aeca3b..40f86ec4ab30 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -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. |