[Bug 75724] [ivb] garbage from ctx restore

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=75724

--- Comment #10 from Ben Widawsky <ben at bwidawsk.net> ---
Right, so the context is garbage with at least 2 cachelines of f's. This of
course should explain IPEHR. I am surprised CCID reflects the garbage context,
I would have expected that to not get loaded until after MI_SET_CONTEXT
completes, but, whatever.

The fact that we have a few corrupt cachelines as opposed to be blocks of
corruption makes me want to blame HW. The biggest problem of course is the LRI
at the top of the context is missing, so no state is actually restored.

We could pretty easily try to detect this specific case, and then just abort
the context restore if it's present. Would such a patch be interesting to
anyone? It would only solve the case where the first cacheline is corrupt.

Kamil btw, does it still occur on -nightly? PPGTT is now turned off there, so
the delta should be less.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20140324/d6aa44fc/attachment.html>