I have a plugable UD-160 running on udl. It requires me to run a xrandr command before I can use the screen. Once I execute the command, the frame rate drops significantly and the mouse can be seen as moving extremely slowly. This did not occur in an older version of the intel driver, so I bisected the code and the offending commit is:
I'm currently running the commit before that, 5891c89ff2be277d1a833d4bc092b65184c1f3d6, and it works fine.
How to reproduce:
1) Have a plugable ud-160
2) Run these xrandr commands:
xrandr --output HDMI1 --mode 1600x1200 --right-of LVDS1
xrandr --output DVI-0 --mode 1600x1200 --right-of HDMI1
3) Monitors set their resolution correctly but the frame rate drops significantly.
Kernel: Linux tigger 3.7.3-030703-generic #201301171415 SMP Thu Jan 17 19:16:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
Please let me know if you need anything else from me.
Which DE are you using, and what app do you feel best captures the performance hit?
Ah, the issue is that pixregion is only clipped inside PixmapSyncDirtyHelper() and so without performing the clipping ourselves we cannot get the dirty ordering right. So,
Author: Chris Wilson <email@example.com>
Date: Fri Jan 18 13:16:23 2013 +0000
uxa: Clip dirty region to slave pixmap before appending damage
Fixes regression from
Author: Dave Airlie <firstname.lastname@example.org>
Date: Mon Jan 7 13:57:21 2013 +1000
intel: fixup damage posting to be done correctly around slave pixmap
which causes the entire slave scanout to be readback from uncached
memory every time a pixel is modified.
Reported-by: Stephen Liang <email@example.com>
Signed-off-by: Chris Wilson <firstname.lastname@example.org>