Nouveau - Nov 2013 - H.264 engine differences between fermi and tesla cards

Hello,

I hope this is an appropriate style of request for this forum. I added
code to support video decoding on the tesla cards that have a
similar-style video decoding engine to fermi cards (i.e. G98, GT21x,
the IGP's -- the falcon-controlled decoding engines, rather than the
xtensa-controlled ones), by using pretty much the same logic that we
had for the fermi cards. This worked great for MPEG-2 and VC-1.
However for H.264 videos, it appears to decode a few frames, and then
the engine hangs.

In traces, I noticed that the nvidia driver reloads the BSP/VP/PPP
engines every second or so. Is this done as a powersaving technique,
or is it done as a workaround for some issue? Does nouveau need to do
the same thing? If so, any specifics on the reload condition?

Any other ideas as to what might be going wrong? Are there some subtle
differences between the fermi and pre-fermi engines? Or a difference
when decoding H.264 files vs MPEG2/VC1 files? Perhaps there's other
information I can provide. BTW, this is with using the firmware blobs
from the NVIDIA proprietary driver.

Thanks,

  -ilia