Bug#658662: drm/i915: no signal via DisplayPort on Sandy Bridge since Linux 3.2

[Peter Colberg <peter@colberg.org>]

On Wed, Apr 18, 2012 at 01:37:23PM -0500, Jonathan Nieder wrote:
> tags 658662 + patch fixed-upstream
> quit
> 
> Hi,
> 
> Peter Colberg wrote:
> 
> > Since upgrading to linux-image-3.2.0-1-amd64, an external display
> > connected via DisplayPort to a Sandy Bridge onboard graphics card
> > stopped working, and instead turns off reporting “DP no signal”.
> >
> > With linux-image-3.1.0-1-amd64, the same display connected via the
> > DisplayPort works fine.
> 
> Thanks again.  This is said to be fixed by the patch "drm/i915:
> properly compute dp dithering for user-created modes" (2012-04-10)
> which has been queued for 3.2.16.

No luck, that patch does *not* fix this problem :-(.

https://bugs.freedesktop.org/show_bug.cgi?id=45801#c16

Peter