Comment 47 for bug 653714

Unfortunately the blob (proprietary driver) does not provide any useful information in these logs.

As mentioned it seems like the tiling (pitch) is misset by ~64 (after a quick look at the attached picture)

Can you do try and establish if the issue happens in or outside of X, and in which cases - i.e. in X only when drawing an image of dimensions x1 & y1, or less than x2 & greater than y2

Meanwhile I'll prep some debug patches (note you may need to rebuild xf86-video-nouveau, libdrm and/or nouveau) :)