Visual glitches when using DMABUFs
The following visual glitches can happen with Intel graphics, with a graphics card that supports and uses a Color Control Surface (CCS) for tile compression (DRM format modifier I915_FORMAT_MOD_Y_TILED_CCS).
It's not entirely clear why these occur, since sometimes there are almost no glitches whatsoever. I suspect either a race condition somewhere, or that misuse (or lack of support with) the GBM api prevents the CCS state from being replicated.
A workaround is to run waypipe with the
--linear-dmabuf command line flag. This flag can also be significantly faster, as reading memory from mapped DMABUFs with non-linear formats can be very slow.