Hi Rafael, On Thursday 21 Apr 2016 23:02:06 Rafael J. Wysocki wrote: > On Thu, Apr 21, 2016 at 10:57 PM, Laurent Pinchart wrote: > > On Thursday 21 Apr 2016 21:52:56 Rafael J. Wysocki wrote: > >> On Thursday, April 21, 2016 02:52:55 AM Laurent Pinchart wrote: > >>> The pm_runtime_force_suspend() and pm_runtime_force_resume() helpers > >>> are designed to help driver being RPM-centric by offering an easy way to > >>> manage runtime PM state during system suspend and resume. The first > >>> function will force the device into runtime suspend at system suspend > >>> time, while the second one will perform the reverse operation at system > >>> resume time. > >>> > >>> However, the pm_runtime_force_resume() really forces resume, regardless > >>> of whether the device was running or already suspended before the call > >>> to pm_runtime_force_suspend(). This results in devices being runtime > >>> resumed at system resume time when they shouldn't. > >>> > >>> Fix this by recording whether the device has been forcefully suspended > >>> in pm_runtime_force_suspend() and condition resume in > >>> pm_runtime_force_resume() to that state. > >>> > >>> All current users of pm_runtime_force_resume() call the function > >>> unconditionally in their system resume handler (some actually set it as > >>> the resume handler), all after calling pm_runtime_force_suspend() at > >>> system suspend time. The change in behaviour should thus be safe. > >>> > >>> Signed-off-by: Laurent Pinchart > >>> <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > >>> Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxxxx> > >> > >> Ulf, any comments? > > > > Ulf has proposed a different approach in "[PATCH] PM / Runtime: Defer > > resuming of the device in pm_runtime_force_resume()". I agree that using > > usage_count is better than introducing a new state flag in struct > > dev_pm_info, with a caveat: it doesn't work properly :-). We would have > > to fix genpd first, as commented in a reply to Ulf's patch. > > OK, thanks! > > Since I'd prefer to avoid adding more state flags too, I'll let you > guys noodle around this for a while more. :-) Let's see what we can do in a reasonable time frame. We could decide to merge this patch as a temporary fix until the genpd rework is complete. -- Regards, Laurent Pinchart
