[PATCH] drm: ignore LVDS on intel graphics systems that lie about having it

[Jesse Barnes]

On Mon, 6 Apr 2009 10:39:17 -0700
Jesse Barnes <jbarnes at virtuousgeek.org> wrote:

> On Mon, 6 Apr 2009 13:29:53 -0400
> Jarod Wilson <jarod at redhat.com> wrote:
> 
> > On Monday 06 April 2009 12:52:16 Jesse Barnes wrote:
> > > On Mon, 6 Apr 2009 10:11:25 -0400
> > > Jarod Wilson <jarod at redhat.com> wrote:
> > > 
> > > > There are a number of small form factor desktop systems with
> > > > Intel mobile graphics chips that lie and say they have an LVDS.
> > > > With kernel mode-setting, this becomes a problem, and makes
> > > > native resolution boot go haywire -- for example, my Dell
> > > > Studio Hybrid, hooked to a 1920x1080 display claims to have a
> > > > 1024x768 LVDS, and the resulting graphical boot on the
> > > > 1920x1080 display uses only the top left 1024x768, and
> > > > auto-configured X will end up only 1024x768 as well. With this
> > > > change, graphical boot and X both do 1920x1080 as expected.
> > > > 
> > > > Note that we're simply embracing and extending the early
> > > > bail-out code in place for the Mac Mini here. The xorg intel
> > > > driver uses pci subsystem device and vendor id for matching,
> > > > while we're using dmi lookups here. The MSI addition is
> > > > courtesy of and tested by Bill Nottingham.
> > > > 
> > > > One minor issue... Current Fedora rawhide, video playback using
> > > > Xv makes X go off into the weeds with this patch added, but
> > > > that's a bug elsewhere, still confident this patch DTRT.
> > > > 
> > > > Signed-off-by: Jarod Wilson <jarod at redhat.com>
> > > > Tested-by: Bill Nottingham <notting at redhat.com>
> > > 
> > > The 2D driver has a similar set of quirks, but since we started
> > > that list we've found that the VBIOS should contain a pretty
> > > reliable table indicating which outputs are available, including
> > > LVDS.  I think if we can figure out how to parse it reliably
> > > (accounting for VBIOS versioning and structure size changes) we
> > > shouldn't need this patch. If we can't get that done in time for
> > > 2.6.30 though I'm all for including this.
> > 
> > Sounds like a plan to me. Either way, would this patch still make
> > sense for submission to the 2.6.29.x stable series? I've already
> > tacked it onto the Fedora 2.6.29 kernel builds, fwiw.
> 
> Yeah would be fine for 2.6.29 as far as I'm concerned, but there's an
> "upstream first" policy for the stable series that might get in the
> way...

Ok we've failed on this one, so we should go ahead an add the LVDS
quirk.  Can you resend this to Eric so it gets into 2.6.30-final?

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center