[Intel-gfx] [PATCH 3/3] drm/i915: remove the vblank_wait hack from HSW+

[Lee, Chon Ming]

On 12/20 12:32, Paulo Zanoni wrote:
> 2013/12/19 Daniel Vetter <daniel at ffwll.ch>:
> > On Thu, Dec 19, 2013 at 10:12 PM, Paulo Zanoni <przanoni at gmail.com> wrote:
> >> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
> >>
> >> When I forked haswell_crtc_enable I copied all the code from
> >> ironlake_crtc_enable. The last piece of the function contains a big
> >> comment with a call to intel_wait_for_vblank. After this fork, we
> >> rearranged the Haswell code so that it enables the planes as the very
> >> last step of the modeset sequence, so we're sure that we call
> >> intel_enable_primary_plane after the pipe is really running, so the
> >> vblank waiting functions work as expected. I really believe this is
> >> what fixes the problem described by the big comment, so let's give it
> >> a try and get rid of that intel_wait_for_vblank, saving around 16ms
> >> per modeset (and init/resume). We can always revert if needed :)
> >>
> >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> >
> > If kms_flip doesn't start failing you're good. Iirc I've added some
> > flip vs. modeset and flip vs. dpms tests specifically for this.
> 
> It already fails on plain -nightly, even without any of my patches on it :(
> 
> I'm testing on a HSW ULT with eDP-only. It's hard to see all the tests
> that fail due to the huge output print by the test, but I can see here
> that at least flip-vs-modeset-vs-hang, flip-vs-panning-vs-hang and
> flip-vs-dpms-off-vs-modeset fail, and also my machine is frozen while
> running single-buffer-flip-vs-dpms-off-vs-modeset... So I can't even
> run kms_flip with my patches and then without them to compare if I
> introduce a new regression
> 
> I also don't see a bug report about this specific Haswell failure, so
> I wonder for how long this is broken :(
> 
> I also feel I have to complain about the fact that kms_flip runs for
> about 45 minutes (before it hangs my machine, so total time may be
> even more). I just wanted to do a quick "check if I broke the test
> which exercises the bug", but then it takes forever to finish... Can
> you please point at specific subtests you were talking about?
> 

I was running kms_flip yesterday to test out BYT.  Getting the same hang after
flip-vs-panning-vs-hang.  Haven't have a chance to bisect it yet.  

But if I running just the flip-vs-panning-vs-hang subtest multiple times, I
don't see the hang.  Only will get the hang when running all subtests.  And it
hang at the same location.

Regards,
Chon Ming


> > -Daniel
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > +41 (0) 79 365 57 48 - http://blog.ffwll.ch
> 
> 
> 
> -- 
> Paulo Zanoni
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