[Intel-gfx] [PATCH 2/2] drm/i915: fixup load-detect on enabled, but not active pipe

[Daniel Vetter]

On Fri, Apr 20, 2012 at 08:44:59PM +0100, Chris Wilson wrote:
> On Fri, 20 Apr 2012 21:03:36 +0200, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> > Somehow we have a fast-path that tries to avoid going through
> > the load-detect code when the encode already has a crtc associated.
> > But this fails horribly when the crtc is off. The load detect pipe
> > itself manages this case well (and also does not forget to restore the
> > dpms state), so just rip out this special case.
> > 
> > The issue seems to go back all the way to the commit that originally
> > introduced load-detection on the vga output:
> > 
> > commit e4a5d54f924ea5ce2913d9d0687d034004816465
> > Author: Ma Ling <ling.ma at intel.com>
> > Date:   Tue May 26 11:31:00 2009 +0800
> > 
> >     drm/i915: Add support for VGA load detection (pre-945).
> > 
> > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43020
> > Reported-by: Jean Delvare <khali at linux-fr.org>
> > Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> I'm happy that intel_get_load_detect_pipe() does the right thing if the
> connector is already active (so that we don't blank an active display
> when checking for disconnections). I was worried that this meant we had
> a deeper bug with our connection state, but as Daniel made me realise it
> is that the "fast path" is lacking the enable.
> 
> For this and subsuquent TV fix, begone foul code,
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

I've picked up this one for -fixes ant the other two for -next, thanks for
the review.
-Daniel
-- 
Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48