[Intel-gfx] [PATCH 14/19] drm: Don't update vblank timestamp when the counter didn't change

[Daniel Vetter]

On Tue, Sep 23, 2014 at 03:48:25PM +0300, Jani Nikula wrote:
> On Mon, 15 Sep 2014, Daniel Vetter <daniel at ffwll.ch> wrote:
> > On Sat, Sep 13, 2014 at 06:25:54PM +0200, Mario Kleiner wrote:
> >> The current drm-next misses Ville's original Patch 14/19, the one i first
> >> objected, then objected to my objection. It is needed to avoid actual
> >> regressions. Attached a trivially rebased (v2) of Ville's patch to go on top
> >> of drm-next, also as tgz in case my e-mail client mangles the patch again,
> >> because it's one of those "email hates me" weeks.
> >
> > Oh dear, I've made a decent mess of all of this really. Picked up to make
> > sure it doesn't get lost again.
> 
> After all this nice ping pong our QA has reported a bisected regression
> on this commit: https://bugs.freedesktop.org/show_bug.cgi?id=84161

Looks like a minuscule timing change which resulted in us detecting a fifo
underrun. Or at least I don't see any other related information that would
indicate otherwise ...
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch