Created attachment 14315 [details]
Cursor corruption appears when the cursor is on particular parts of the screen. The corruption appears as blinking lines next to, or on top of the cursor. These distortions don't change in patter if the cursor is moved strictly up and down (same horizontal pixel), but change if the cursor is moved to left or right, even by 1 pixel. The affected areas of the screen are columns ~10px wide around every 255px (x % 255 == 0, but not x === 0).
The corruption seems to be limited to the cursor only - it doesn't stay around when the cursor is moved away, and doesn't appear on screenshots.
Different cursors (arrow, text selection, etc) seem to be all affected by the problem.
01:00.0 VGA compatible controller: ATI Technologies Inc Radeon Mobility X1400
hardware is Dell laptop, model Inspiron e1505
driver ver. (commit) a9af866ae712a0048d374dc640e482d1f4ce8859
The problem was first noticed around Dec '07, but I have not tried any versions since (IOW, I don't know if the problem has been fixed since, but came back -- or if it hasn't been fixed yet)
I can confirm this on the external DVI LCD monitor attached to my Thinkpad T60p with a FireGL 5200 (similar chip as the X1600). It is not doing it on the laptop's own 1400x1050 LCD panel (which is RightOf the 1920x1200 Doublesight). git version of the driver, git_commit caa10014d115a49a59b4a2aef6ce36a4e615556a, dated Jan 30th.
Good catch on the mod 255 pixel thing! It is definitely true but I never noticed the correlation before. Just put up "xev" to get the pixel location to be sure.
It appears like the corruption (also appearing to me as horizontal white and block stripes, one to several pixels high, 3-5 strips per the height of the curson and flickering) happens in a block around the cursor shape, staying put on the screen as the cursor moves about inside that block. The zone of corruption appears to be the cursor width across times the whole height of the screen.
(II) RADEONHD(0): Using HW cursor
This is the same as bug 13405
(In reply to comment #2)
> This is the same as bug 13405
Yes, looks like it is the same bug
*** This bug has been marked as a duplicate of bug 13405 ***