[Intel-gfx] [PATCH 1/2] drm/i915: check whether we actually received an edid in detect_ddc

[Daniel Vetter]

On Wed, Jul 11, 2012 at 11:44:36AM +0100, Chris Wilson wrote:
> On Wed, 11 Jul 2012 12:31:52 +0200, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > Somehow detect_ddc manages to fall through all checks when we think
> > that something responds on the ddc i2c address, but the edid read
> > failed. Fix this up by explicitly checking for this case.
> > 
> > This fixes a regression on newer chips because since
> > 
> > commit aaa377302b2994fcc2c66741b47da33feb489dca
> > Author: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Date:   Sat Jun 16 15:30:32 2012 +0200
> > 
> >     drm/i915/crt: Do not rely upon the HPD presence pin
> > 
> > we use ddc detection also on hotplug capable platforms. And one of
> > these reads all 0s for any i2c transaction if nothing is connected to
> > the vga port.
> > 
> > v2: Implement Chris Wilson's review:
> > - simplify logic, default to "nothing detected"
> > - kill stale comment
> > - BUG_ON(!crt->type != ANALOG)
> > 
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=51900
> > Tested-by: Yang Guang <guang.a.yang at intel.com>
> > Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> I'm happy with that, and thanks for the extra clarification in the debug
> messages.
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

Both patches merged to dinq, thanks a lot for the review.
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48