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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - [IVB/BXT] performance failure when running kms_setmode basic"
href="https://bugs.freedesktop.org/show_bug.cgi?id=98553#c15">Comment # 15</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - [IVB/BXT] performance failure when running kms_setmode basic"
href="https://bugs.freedesktop.org/show_bug.cgi?id=98553">bug 98553</a>
from <span class="vcard"><a class="email" href="mailto:joseph1.garvey@intel.com" title="Joseph Garvey <joseph1.garvey@intel.com>"> <span class="fn">Joseph Garvey</span></a>
</span></b>
<pre>(In reply to Chris Wilson from <a href="show_bug.cgi?id=98553#c7">comment #7</a>)
<span class="quote">> It's a new test. It may simply be asking for much precision. The failure is
> an error of +-20us, which is greater than a scanline and our accuracy goal
> is roughly half a scanline.</span >
The first assertion, that "99.7% samples within one scanline on each side of
mean", is also failing (on BDW and HSW from what I've tried). If you relax it
to 95%, the test passes - but that's a pretty low MTBF. What makes 5.6s the
lowest acceptable MTBF? Also, how much does vblank accuracy depend on the
hardware and should the test take that into consideration?</pre>
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