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Date: Tue, 3 Jun 2014 15:18:17 +0800 From: "Wang, Yalin" <Yalin.Wang@...ymobile.com> To: "'len.brown@...el.com'" <len.brown@...el.com>, "'pavel@....cz'" <pavel@....cz>, "'rjw@...k.pl'" <rjw@...k.pl>, "'linux-pm@...r.kernel.org'" <linux-pm@...r.kernel.org>, "'linux-kernel@...r.kernel.org'" <linux-kernel@...r.kernel.org> Subject: autosleep suspend too frquent problem Hi I found sd card sometimes are damaged/ destroyed On our devices . And seems it is caused by kernel's frequently suspend/resume, Because during suspend/resume, the driver will suspend/resume sdcard Very frequently, this will damaged the sdcard sometimes, and the damage is not recoverable .. Sometimes kernel will enter suspend and exit suspend very frequently, Especially when the system is in idle, but some driver is not idle, And it will wake up the system by irq frequently. By our power test result, if system enter suspend /resume very frequently, Will consume more power , because it will enable /disable many devices During a short time . I make a patch to prevent the system to enter suspend/resume state More than one time during 2 seconds: diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c index ca304046..78fb06a 100644 --- a/kernel/power/autosleep.c +++ b/kernel/power/autosleep.c @@ -11,7 +15,7 @@ #include <linux/pm_wakeup.h> #include "power.h" - +#define SUSPEND_TIME_SLICE (2 * HZ) static suspend_state_t autosleep_state; static struct workqueue_struct *autosleep_wq; /* @@ -26,7 +30,8 @@ static struct wakeup_source *autosleep_ws; static void try_to_suspend(struct work_struct *work) { unsigned int initial_count, final_count; - + int ret; + static unsigned long last_suspend_exit_time; if (!pm_get_wakeup_count(&initial_count, true)) goto out; @@ -43,8 +48,24 @@ static void try_to_suspend(struct work_struct *work) } if (autosleep_state >= PM_SUSPEND_MAX) hibernate(); - else - pm_suspend(autosleep_state); + else { + if (last_suspend_exit_time == 0 || + time_after(jiffies, + last_suspend_exit_time + SUSPEND_TIME_SLICE)) { +suspend: + ret = pm_suspend(autosleep_state); + if (ret == 0) + last_suspend_exit_time = jiffies; + } else { + unsigned long sleep_time = + SUSPEND_TIME_SLICE - + (jiffies - last_suspend_exit_time); + if (sleep_time > 0) + schedule_timeout_uninterruptible(sleep_time); + else + goto suspend; + } + } mutex_unlock(&autosleep_lock); seems works ok , my question is that should we change the autosleep module to make sure not enter suspend/resume in a short time, or it is driver's problems? The driver should not wake up system very frequently ? Thanks Wang Yalin Engineer OSDD Sony Mobile Communications -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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