<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO --- - [SNB, IVB] Page flips hang indefinitely, apparently waiting for mmio writes that never happen"
href="https://bugs.freedesktop.org/show_bug.cgi?id=75502#c27">Comment # 27</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO --- - [SNB, IVB] Page flips hang indefinitely, apparently waiting for mmio writes that never happen"
href="https://bugs.freedesktop.org/show_bug.cgi?id=75502">bug 75502</a>
from <span class="vcard"><a class="email" href="mailto:simon@farnz.org.uk" title="Simon Farnsworth <simon@farnz.org.uk>"> <span class="fn">Simon Farnsworth</span></a>
</span></b>
<pre>(In reply to <a href="show_bug.cgi?id=75502#c26">comment #26</a>)
<span class="quote">> They confirm that the dspsurf is still at 0x00372000. The earlier theories
> that another write happened are debunked. So it has to be something in the
> simple MI_DISPLAY_FLIP command packets that causes the CS to simply ignore
> it.
>
> Try,
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c
> index 0326ea8..1a680bf 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -8842,6 +8842,10 @@ static int intel_gen6_queue_flip(struct drm_device
> *dev,
> if (ret)
> goto err;
>
> + ret = intel_ring_cacheline_align(ring);
> + if (ret)
> + goto err_unpin;
> +
> ret = intel_ring_begin(ring, 4);
> if (ret)
> goto err_unpin;
>
> (current drm-intel-nightly already has that for ivb)</span >
Tested, and still fails.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>