Slow Window Resizing with KWin Compositing on FGLRX
Amongst users of the proprietary ATI driver (FGLRX), it’s a well known problem that KDE4’s KWin’s desktop effects are unusable due to turtle slow window resizing. Unfortunately, bug reports and forum posts fail to come up with a clear answer as to why this happens, who is responsibility for fixing it, and which parts of the stack need to adapt for the bug. If you’re not already familiar with the problem, observe:
As you can see, the three second delay in window resizing, maximizing, and (perhaps) restoring makes compositing-enabled KWin unusable. Note that the problem still persists when disabling the “show window content while resizing” option.
It’s been particularly difficult to track down the route of this problem and who should be fixing it. From a lengthy discussion on Phoronix’s Forums, ATI’s “Bridgman” user acknowledges the problem but claims “It’s not a driver issue AFAIK, so not sure why we would mention it in the release notes.” He goes on to indicate that the problem was introduced during a hack to ensure KWin compatibility on Intel cards, to work around a glitch with garbage appearing on the screen, and a lengthy debate over the “107_fedora_dont_backfill_bg_none.patch” patch. Somewhere the stack was patched to support Intel cards at the expense of ATI cards, according to ATI’s “Bridgman”.
Over on the KDE bugzilla, we’re met with a curt response from the KWin team: “Driver bug then.” The bug is marked as “RESOLVED” and “UPSTREAM”.
And elsewhere on the Internet, we get a helpless string of “still not fixed” messages, over on the unofficial FGLRX bugzilla, other Phoronix forum posts, and distro forums.
So I ask my readers: who is responsible for this bug and how will it be fixed? If indeed it is neither FGLRX nor KWin and the problem exists in XOrg, why has XOrg been patched to support Intel cards at the expense of ATI cards? Is there anything FGLRX or KWin could be doing to mitigate the problem? Potential workarounds? Users have complained of this problem for over a year now perhaps, but not once has leadership from anywhere offered a compelling explanation or plan for the future. What to do?
Leave comments. The current discussion seems to be fruitful.



























