https://bugs.freedesktop.org/show_bug.cgi?id=79223
--- Comment #7 from Pierre Ossman pierre-bugzilla@ossman.eu --- Anyhoo, getting back to the matter at hand.
I set up a new machine so I can more easily do debugging of this. The hardware is instead:
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Richland [Radeon HD 8510G]
Not identical, but should be a very similar chip (ARUBA vs TURKS).
I am still seeing the frame rate problem on this machine. It is however not constant, and comes and goes. I am running a lower resolution here, which might be a factor.
Also, for some reason I am not getting delays in glReadPixels(). So whatever goes wrong must be happening some place else.
I turned on some of the gallium overlays. Not sure if this tells you anything:
- Normal playback: buffer wait time of 15k-20k
- With glReadPixels(): ~35k
- When the bug strikes: jumps to ~50k
The frame rate frop and buffer wait time increases are perfectly synchronised every time.