Messages in this thread | | | Subject | Re: [PATCH] PM: avoid 'autosleep' in shutdown progress | From | Yanmin Zhang <> | Date | Fri, 12 Jul 2013 14:14:11 +0800 |
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On Thu, 2013-07-11 at 16:03 +0800, shuox.liu@intel.com wrote: > From: Liu ShuoX <shuox.liu@intel.com> > > In shutdown progress, system is possible to do power transition > (such as suspend-to-ram) in parallel. It is unreasonable. So, > fixes it by adding a system_state checking and queue try_to_suspend > again when system status is not running. > > Signed-off-by: Liu ShuoX <shuox.liu@intel.com> > --- > kernel/power/autosleep.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > Without this patch, we hit an hang issue on Android.
Scenario: Kernel starts shutdown and calls all device driver's shutdown callback. When a driver's shutdown is called, the last wakelock is released and suspend-to-ram starts. However, as some driver's shut down callbacks already shut down devices and disable runtime pm, the suspend-to-ram calls driver's suspend callback without noticing that device is already off and causes crash. We know the drivers should be fixed, but can we also change generic codes a little to make it stronger?
> diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c > index c6422ff..9012ecf 100644 > --- a/kernel/power/autosleep.c > +++ b/kernel/power/autosleep.c > @@ -32,7 +32,8 @@ static void try_to_suspend(struct work_struct *work) > > mutex_lock(&autosleep_lock); > > - if (!pm_save_wakeup_count(initial_count)) { > + if (!pm_save_wakeup_count(initial_count) || > + system_state != SYSTEM_RUNNING) { > mutex_unlock(&autosleep_lock); > goto out; > }
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