[Intel-gfx] Fighting tearing

[Ben Widawsky]

On 2012-09-09 08:48, Roberth Sjonøy wrote:
> Hello
>
> I run Arch Linux, with it's latest x.org and kernel, and I have
> compiled libdrm and the intel driver from git, and I update it today.
>
> Buit this is issue exists even with the releases.
>
> WIth UXA, rendering of the windows in my XFCE4-desktop goes just
> fines, good performance, windows (exspecially GTK+) doesn't hang 
> after
> if I drag them over the screen, but there is lot of small tearing.
> And I want this to go away, I do not use any kind of composition, and
> I am using XFCEs window manager.
>
> Here is my xorg.conf
>
>
> Section "ServerFlags"
>     Option "AutoAddDevices" "Off"
> EndSection
>
> Section "InputDevice"
>     Identifier     "Keyboard0"
>     Driver         "keyboard"
>     Option         "XkbLayout" "no"
> EndSection
>
> Section "Device"
>     Identifier  "Card0"
>     Driver      "intel"
>     Option      "AccelMethod" "UXA"
>     Option      "TearFree" "true"
>     Option      "MigrationHeuristic" "greedy"
>     Option	"TripleBuffer" "true"
> EndSection
>
> With SNA, the performance of the applications is muc much worse. If I
> just replace UXA with SNA.
>
> Thanks in advance for any help.
>
> Regards,
>
> Roberth Sjonøy0

Unfortunately it's often the case that tearing is pretty much 
unavoidable without a compositor. AFAIK you'd just be getting lucky with 
SNA, as opposed to UXA.

However, for the SNA slowness, you should file a bug and include the 
following information:
lspci -n -s 2.0
/var/log/Xorg.0.log
dmesg with drm.debug=0xe sometime after experiencing the slowness
<feel free to mention UXA is much faster>

-- 
Ben Widawsky, Intel Open Source Technology Center