Bug 10245

Created attachment 9078 [details]
Mouse cursor glitches.

I had an idea and I restarted X with EXA instead of XAA; I tried both stellarium and lowfat and I could not reproduce the problem. However I don't if it is because the problem is related to XAA or if I was just lucky.

Normally I don't use EXA because Render Acceleration is unsupported with R300 cards and moving windows around is jerkier than with XAA.

xorg.conf relevant section (XAA):

Section "Device"
    Identifier  "ATI Radeon X550"
    Driver      "radeon"
    Option      "RenderAccel"    "on"
    Option      "AccelMethod"    "xaa"
    Option      "EnablePageFlip" "True"
    Option      "XAANoOffscreenPixmaps"
EndSection


xorg.conf relevant section (EXA):

Section "Device"
    Identifier  "ATI Radeon X550"
    Driver      "radeon"
    Option      "RenderAccel"    "on"
    Option      "AccelMethod"    "exa"
    Option      "AccelDFS"       "on" 
    Option      "EnablePageFlip" "on"
EndSection

Created attachment 9080 [details]
New mouse glitches.

> The glitches pattern is random, but once they appear the pattern doesn't change
> until the application is closed and restarted. In the next comment I'll attach
> a pictures of the mouse cursor area.

Apparently I was wrong, it seems that the glitches change over time. I was playing with lowfat and initially the glitches were similar to the previous screenshot, then after some minutes they were like the screenshot attached to this comment.

Please attach the full Xorg.0.log.

Created attachment 9102 [details]
Xorg.0.log

I upgraded to xorg-server 1.2.99.901, no changes.

Does this also happen with Option "ColorTiling" "off" or without page flipping?

(In reply to comment #6)
> Does this also happen with Option "ColorTiling" "off" or without page flipping?
> 

ColorTiling On   PageFlipping On:	glitches
ColorTiling On   PageFlipping Off:	no glitches
ColorTiling Off  PageFlipping On:	no glitches
ColorTiling Off  PageFlipping Off:      no glitches

PS. Is it normal if there was no message acknowledging that ColorTiling was disabled?

(In reply to comment #7)
> (In reply to comment #6)
> > Does this also happen with Option "ColorTiling" "off" or without page flipping?
> > 
> 
> ColorTiling On   PageFlipping On:       glitches
> ColorTiling On   PageFlipping Off:      no glitches
> ColorTiling Off  PageFlipping On:       no glitches
> ColorTiling Off  PageFlipping Off:      no glitches
> 
> PS. Is it normal if there was no message acknowledging that ColorTiling was
> disabled?
I thought no, but looking at the code apparently it is...

Do you run lowfat/stellarium in full screen mode? If so could you try it windowed? It may be possible due to some bug the 3d driver writes beyond the screen area by 1 line, which due to tiling would mess up the hw cursor area (just behind the front screen buffer). At least that would explain why it only happens with both pageflip and tiling (without pageflip, typical gl apps only render to back buffer, without tiling, it wouldn't hit the cursor area since there are 2 lines reserved after front buffer).

Created attachment 9104 [details]
Window border glitches.

> Do you run lowfat/stellarium in full screen mode? If so could you try it
> windowed? It may be possible due to some bug the 3d driver writes beyond the
> screen area by 1 line, which due to tiling would mess up the hw cursor area
> (just behind the front screen buffer). At least that would explain why it only
> happens with both pageflip and tiling (without pageflip, typical gl apps only
> render to back buffer, without tiling, it wouldn't hit the cursor area since
> there are 2 lines reserved after front buffer).

I think you're right: I'm doing these tests with lowfat, because I can quickly cause the glitches with it, and launching the program in a window the mouse glitches DO NOT appear.
Moreover, the lowfat window isn't "grabbed" by metacity and just one pixel out the window border you can see some moving dots (see attached screenshot).

> Moreover, the lowfat window isn't "grabbed" by metacity and just one pixel out
> the window border you can see some moving dots (see attached screenshot).
> 

These white dots happen only with both ColorTiling and PageFlipping enabled, so apparently they're related.

Hello, I upgraded yesterday to xf86-video-ati 6.6.191 and I can't reproduce the first problem (glitches in the mouse pointer area) anymore. The glitches 1 pixel out of the window border when not using fullscreen are still there, however.

Bugzilla Upgrade Mass Bug Change

NEEDSINFO state was removed in Bugzilla 3.x, reopening any bugs previously listed as NEEDSINFO.

  - benjsc
    fd.o Wrangler

Problem disappeared sometime in the last months.