[ILK] Triangle tearing and sampler corruption (kwin full-scene repaint)
Submitted by RussianNeuroMancer @RussianNeuroMancer
Assigned to Chris Wilson @ickle
Description
Triangle tearing (this is not exact definition of what you can see on attached screenshots, but the point is - this artifact seems like occur under similar conditions as typical tearing, and most of the time looks like triangle) is observer for example while fast scrolling or selecting text in Konsole or scrolling folder with many files in Dolphin, and so on. But, for some reason, not while video playback (xv, opengl and vaapi video outputs tested).
Reproducible in: Mesa 10.3.2 and driver version 2.99.914-1exp1ubuntu4.1 with SNA acceleration, Mesa 10.5git1501311930.609461 and driver version .99.917+git1501311931.dac01d with both of SNA and GLAMOR acceleration.
Not reproducible in: Mesa 10.3.2 and driver version 2.99.914-1exp1ubuntu4.1 with GLAMOR acceleration.exp1ubuntu4.1 with GLAMOR acceleration there is no tearing on stock Linux 3.16.0-30 from repo and on Linux 3.18.5. Boot Linux 3.16.0-30 with Mesa 10.5
(Actually, I not sure issue in driver, because I just compare default Kubuntu 14.10 packages set (libdrm, video driver, mesa, etc.) and set from Oibaf PPA, but since there is difference between SNA and GLAMOR I this is issue in the driver.)
Change kernel version seems like doesn't make any difference. For example with Mesa 10.3.2 and driver version 2.99.914-1git1501311930.609461 and driver version 2.99.917+git1501311931.dac01d gave tearing anyway. git1501311930.609461 and driver version 2.99.917+git1501311931.dac01d with SNA, but TearFree doesn't help.
I tried TearFree with Mesa 10.5
In SNA mode I tested kwin, and in GLAMOR mode I tested kwin_gles (4.11.12) in both cases in Full repaint V-Sync mode in KWin settings.
With disabled desktop effects I doesn't see this artifact (not reproducible or I just can't notice it).