[PATCH v2 12/15] drm/mgag200: Remove out-commented suspend/resume helpers

[Daniel Vetter]

On Wed, May 13, 2020 at 10:15:25AM +0100, Emil Velikov wrote:
> On Tue, 12 May 2020 at 19:47, Thomas Zimmermann <tzimmermann at suse.de> wrote:
> >
> > Hi
> >
> > Am 12.05.20 um 12:14 schrieb Emil Velikov:
> > > Hi Thomas,
> > >
> > > On Tue, 12 May 2020 at 09:43, Thomas Zimmermann <tzimmermann at suse.de> wrote:
> > >>
> > >> The suspend/resume helpers are unused. Also remove associated state
> > >> from struct mga_device.
> > >>
> > > Although DPMS in it's traditional sense is no longer a thing, would it
> > > make sense to keep this around for documentation purposes?
> > > In particular, the pci magic and associated PLL/DAC/pixel clock could
> > > be used for dynamic PM.
> >
> > That patch is not about DPMS. The DPMS code is still there. The
> > suspend/resume helpers were outcommented and I don't know if they ever
> > worked. Let's remove them.
> >
> Seems like the idea is to suspend/resume the device on DPMS off/on. A
> rather moot point IMHO.
> As the DPMS semantics and the whole modeset, got more subtle with
> atomic modeset, the idea gets even more moot.

With atomic it's actually a lot easier to do runtime pm in your
modesetting code, since the flow is a lot more structured. There's even a
helper function for that with drm_atomic_helper_commit_tail_rpm, since the
default is optimized for max compatability with old legacy helpers. Maybe
we should switch that around actually.
-Daniel

> If the documentation has that process - sure nuke it. Although for
> dynPM, this code is essential.
> Considering a) one has interest in dynPM and b) the code is (close to) working.
> 
> The last two are very big ifs so I'll leave it there.
> 
> -Emil

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch