<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - Horizontal lines in radeon driver on kernel 3.15 and upwards"
href="https://bugs.freedesktop.org/show_bug.cgi?id=87682#c17">Comment # 17</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - Horizontal lines in radeon driver on kernel 3.15 and upwards"
href="https://bugs.freedesktop.org/show_bug.cgi?id=87682">bug 87682</a>
from <span class="vcard"><a class="email" href="mailto:chris.bainbridge@gmail.com" title="Chris Bainbridge <chris.bainbridge@gmail.com>"> <span class="fn">Chris Bainbridge</span></a>
</span></b>
<pre>Christian König posted an explanation of the PLL divider values at
<a href="https://bugzilla.kernel.org/show_bug.cgi?id=91861#c12">https://bugzilla.kernel.org/show_bug.cgi?id=91861#c12</a> (another "no screen after
3.15" bug report)
The various fixes adjust the divider value limits slightly for different
displays. The basic formula is commented in the radeon_compute_pll_avivo
function:
dot_clock = (ref_freq * feedback_div) / (ref_div * post_div)
So by adjusting the limits of those values you can find something that works
for your laptop display. But I don't know which solution is technically correct
- if you don't get a reply here you could try emailing Christian König and
asking.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>