[REGRESSION] i915 KMS dual head broken on DELL latitude E6420 in 3.1-rc*

[Samuel Thibault]

Keith Packard, le Thu 15 Sep 2011 00:43:36 -0500, a écrit :
> On Thu, 15 Sep 2011 01:27:17 +0200, Samuel Thibault <samuel.thibault at ens-lyon.org> wrote:
> Non-text part: multipart/mixed
> > Hello,
> > 
> > I'm trying to upgrade from 3.0 to 3.1-rcsomething on a DELL latitude
> > E6420, but dual head is broken. Here is the scenario:
> > 
> > - Turn computer on with VGA1 connected. Both LVDS1 and VGA1 show the
> >   text console fine.
> > - Start X. VGA1 shows X fine, but LVDS1 (1600x900 resolution) shows an
> >   odd screen: completely black on the left part (about 1060x900), sort
> >   of gray on the right part (about 540x900). Playing with xrandr doesn't
> >   help, I can at best make it completely black with --off, and not get
> >   it back again with --auto or anything else.
> 
> Can you try disabling frame buffer compression?
> 
> i915.i915_enable-fbc=0
> 
> I'm about to send a patch to disable this by default; I've gotten two
> people saying that this helps them already.

Absolutely. I have no issue any more, and the error messages are gone.

Samuel