Re: [PATCH] PM: use pm_runtime_put_sync in system resume

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday 15 December 2009, Alan Stern wrote:
> This patch (as1317) fixes a bug in the PM core.  When a device is
> resumed following a system sleep, the core decrements the device's
> runtime PM usage counter but doesn't issue an idle notification if the
> counter reaches 0.  This could prevent an otherwise unused device from
> being runtime-suspended again after the system sleep.
> 
> The fix is to call pm_runtime_put_sync() instead of
> pm_runtime_put_noidle().
> 
> Signed-off-by: Alan Stern <stern@rowland.harvard.edu>

Applied to suspend-2.6/linux-next, will be pushed to Linus before -rc2.

Rafael


> ---
> 
> Index: usb-2.6/drivers/base/power/main.c
> ===================================================================
> --- usb-2.6.orig/drivers/base/power/main.c
> +++ usb-2.6/drivers/base/power/main.c
> @@ -521,7 +521,7 @@ static void dpm_complete(pm_message_t st
>  			mutex_unlock(&dpm_list_mtx);
>  
>  			device_complete(dev, state);
> -			pm_runtime_put_noidle(dev);
> +			pm_runtime_put_sync(dev);
>  
>  			mutex_lock(&dpm_list_mtx);
>  		}
> @@ -772,7 +772,7 @@ static int dpm_prepare(pm_message_t stat
>  		pm_runtime_get_noresume(dev);
>  		if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) {
>  			/* Wake-up requested during system sleep transition. */
> -			pm_runtime_put_noidle(dev);
> +			pm_runtime_put_sync(dev);
>  			error = -EBUSY;
>  		} else {
>  			error = device_prepare(dev, state);