<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - [GLK] Fifo underrun when changing resolution"
href="https://bugs.freedesktop.org/show_bug.cgi?id=100302#c4">Comment # 4</a>
on <a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - [GLK] Fifo underrun when changing resolution"
href="https://bugs.freedesktop.org/show_bug.cgi?id=100302">bug 100302</a>
from <span class="vcard"><a class="email" href="mailto:conselvan2@gmail.com" title="Ander Conselvan de Oliveira <conselvan2@gmail.com>"> <span class="fn">Ander Conselvan de Oliveira</span></a>
</span></b>
<pre>I still haven't found the root cause for this, but I was enable to narrow it
down further:
- The underrun only happens with eDP because it is triggered by using the pipe
scaler. If I force HDMI to use panel fitting, the underrun is also triggered.
- The underrun happens only the first time the scaler is used. After reverting
to the panel native resolution, a subsequent modeset won't trigger the underrun
again. However, the underrun can be triggered once after a suspend/resume
cycle.
- Using the scaler to scale a plane before the modeset that triggers the scaler
usage by the pipe will also prevent the underrun.</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>