[Intel-gfx] [PATCH 1/4] drm/i915: fixup interlaced vertical timings confusion
daniel at ffwll.ch
Fri Jan 27 11:08:42 PST 2012
On Thu, Jan 26, 2012 at 11:11:30PM +0100, Daniel Vetter wrote:
> On Thu, Jan 26, 2012 at 10:03:02PM +0000, Chris Wilson wrote:
> > On Thu, 26 Jan 2012 22:01:30 +0100, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > > - /* XXX some encoders set the crtcinfo, others don't.
> > > - * Obviously we need some form of conflict resolution here...
> > > - */
> > > - if (adjusted_mode->crtc_htotal == 0)
> > > + /* gen2 needs vertical crtc timing information in fields because that's
> > > + * what dvo outputs want - the chip itself can't do interlaced. All
> > > + * later generations can do interlaced natively and want timings in
> > > + * full frames. */
> > > + if (IS_GEN2(dev))
> > > + drm_mode_set_crtcinfo(adjusted_mode, CRTC_INTERLACE_HALVE_V);
> > > + else
> > > drm_mode_set_crtcinfo(adjusted_mode, 0);
> > >
> > > diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
> > > index 6eda1b5..020a7d7 100644
> > > --- a/drivers/gpu/drm/i915/intel_dvo.c
> > > +++ b/drivers/gpu/drm/i915/intel_dvo.c
> > > @@ -157,7 +157,6 @@ static bool intel_dvo_mode_fixup(struct drm_encoder *encoder,
> > > C(vsync_end);
> > > C(vtotal);
> > > C(clock);
> > > - drm_mode_set_crtcinfo(adjusted_mode, CRTC_INTERLACE_HALVE_V);
> > > #undef C
> > > }
> > Removing drm_mode_set_crtcinfo() scares me because of the above comment.
> > We need to make sure that the adjusted_mode is initialised along
> > some path, and the fixup in intel_crtc_mode_fixup is just a hack.
> > commit 897493504addc5609f04a2c4f73c37ab972c29b2
> > Author: Chris Wilson <chris at chris-wilson.co.uk>
> > Date: Sun Sep 12 18:25:19 2010 +0100
> > drm/i915: Ensure that the crtcinfo is populated during mode_fixup()
> > This should fix the mysterious mode setting failures reported during
> > boot up and after resume, generally for i8xx class machines.
> > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=16478
> > Reported-and-tested-by: Xavier Chantry <chantry.xavier at gmail.com>
> > Buzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29413
> > Tested-by: Daniel Vetter <daniel at ffwll.ch>
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: stable at kernel.org
> > If you can work out exactly where it should be initialised, you'll be my
> > hero!
> Afaik drm core calling set_crtcinfo is just a side-effect of some random
> actions and it's not guaranteed to happen. The issue is that drm core puts
> the wrong stuff in there. Also note that I'm now unconditionally doing the
> fixup, so the particular bug above shouldn't show up again.
> I'll check whether this is indeed the case on my dear old i855gm - let's
> see whether I'm provoking the wrath of some ill-tempered gods here ;-)
Seems the volcano gods haven't noticed yet what I'm doing here, i.e. works
on my i855gm.
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48
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