<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - [SKL][Linux] : Xrandr is not working as expected"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91562#c17">Comment # 17</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - [SKL][Linux] : Xrandr is not working as expected"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91562">bug 91562</a>
from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
<pre>(In reply to Tvrtko Ursulin from <a href="show_bug.cgi?id=91562#c16">comment #16</a>)
<span class="quote">> (In reply to Chris Wilson from <a href="show_bug.cgi?id=91562#c15">comment #15</a>)
> > (In reply to Tvrtko Ursulin from <a href="show_bug.cgi?id=91562#c14">comment #14</a>)
> > > Created <span class=""><a href="attachment.cgi?id=118122" name="attach_118122" title="ddx debug log in Y tiling mode">attachment 118122</a> <a href="attachment.cgi?id=118122&action=edit" title="ddx debug log in Y tiling mode">[details]</a></span>
> > > ddx debug log in Y tiling mode
> > >
> > > With the DDX rebuilt to default to Y tiling, this logs shows that when
> > > "xrandr -o left" it abandons the Y tiled FB and goes back to X tiled.
> >
> > It sets the rotation, and then the kernel rejects the setcrtc and so it is
> > forced to use a shadowfb, X without rotation, and perform manual rotations
> > (using the GPU of course!) from the Y-tiled frontbuffer to the X-tiled
> > framebuffer.
>
> Does it try to go Y tiled when attempting to rotate, in the default build? </span >
It's tricky. The buffer cannot be exported and Y-tiling is so much slower for
common operations that I am not convinced it is worth it. It is possible for
the client to provide a Y-tiled buffer that we will then use. But since the
setcrtc failed...
<span class="quote">> Interestingly in the Y tiled build there seems to be a path where it doesn't
> use fb modifiers ("[drm:intel_framebuffer_init] No Y tiling for legacy
> addfb").</span >
Right, during the start up it tests whether the interface is deliberately
broken.</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>