Re: [PATCH] drm/omap: Fix issue with clocks left on after resume

[Tony Lindgren <tony@atomide.com>]

* Tony Lindgren <tony@atomide.com> [210427 10:54]:
> * Tony Lindgren <tony@atomide.com> [210427 10:12]:
> > * Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> [210427 08:47]:
> > > If I understand right, this is only an issue when the dss was not enabled
> > > before the system suspend? And as the dispc is not enabled at suspend,
> > > pm_runtime_force_suspend and pm_runtime_force_resume don't really do
> > > anything. At resume, the DRM resume functionality causes omapdrm to call
> > > pm_runtime_get and put, and this somehow causes the dss to stay enabled.
> > 
> > We do have dss enabled at system suspend from omap_atomic_comit_tail()
> > until pm_runtime_force_suspend(). Then we have pm_runtime_force_resume()
> > enable it.
> 
> Sorry I already forgot that pm_runtime_force_resume() is not enabling
> it because pm_runtime_need_not_resume().. It's the omapdrm calling
> pm_runtime_get() that enables the hardware on resume.
> 
> > Then on resume PM runtime prevents disable of the hardware on resume path
> > until after device_complete(). Until then we have rpm_suspend() return
> > -EBUSY, and so the parent child_count is not going to get decreased.
> > Something would have to handle the -EBUSY error here it seems.

I sent out v2 patch with an updated description.

Regards,

Tony