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authorShuoX Liu <shuox.liu@intel.com>2011-08-10 23:01:26 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2011-10-16 23:27:45 +0200
commit2a77c46de1e3dace73745015635ebbc648eca69c (patch)
treea801ed6ba5623c7d963377906776ade6f02eea0a /kernel/power/suspend.c
parent9bd717c0dc8224cadfd66df7eeff98c987711d98 (diff)
PM / Suspend: Add statistics debugfs file for suspend to RAM
Record S3 failure time about each reason and the latest two failed devices' names in S3 progress. We can check it through 'suspend_stats' entry in debugfs. The motivation of the patch: We are enabling power features on Medfield. Comparing with PC/notebook, a mobile enters/exits suspend-2-ram (we call it s3 on Medfield) far more frequently. If it can't enter suspend-2-ram in time, the power might be used up soon. We often find sometimes, a device suspend fails. Then, system retries s3 over and over again. As display is off, testers and developers don't know what happens. Some testers and developers complain they don't know if system tries suspend-2-ram, and what device fails to suspend. They need such info for a quick check. The patch adds suspend_stats under debugfs for users to check suspend to RAM statistics quickly. If not using this patch, we have other methods to get info about what device fails. One is to turn on CONFIG_PM_DEBUG, but users would get too much info and testers need recompile the system. In addition, dynamic debug is another good tool to dump debug info. But it still doesn't match our utilization scenario closely. 1) user need write a user space parser to process the syslog output; 2) Our testing scenario is we leave the mobile for at least hours. Then, check its status. No serial console available during the testing. One is because console would be suspended, and the other is serial console connecting with spi or HSU devices would consume power. These devices are powered off at suspend-2-ram. Signed-off-by: ShuoX Liu <shuox.liu@intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'kernel/power/suspend.c')
-rw-r--r--kernel/power/suspend.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index b6b71ad2208f..595a3dd56a8a 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -104,7 +104,10 @@ static int suspend_prepare(void)
goto Finish;
error = suspend_freeze_processes();
- if (!error)
+ if (error) {
+ suspend_stats.failed_freeze++;
+ dpm_save_failed_step(SUSPEND_FREEZE);
+ } else
return 0;
suspend_thaw_processes();
@@ -315,8 +318,16 @@ int enter_state(suspend_state_t state)
*/
int pm_suspend(suspend_state_t state)
{
- if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
- return enter_state(state);
+ int ret;
+ if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) {
+ ret = enter_state(state);
+ if (ret) {
+ suspend_stats.fail++;
+ dpm_save_failed_errno(ret);
+ } else
+ suspend_stats.success++;
+ return ret;
+ }
return -EINVAL;
}
EXPORT_SYMBOL(pm_suspend);