sna: Disable userspace w/a for i830/845 cs incoherencydisable-gen20-wa

In

commit c7f7dd61fd07dbf938fc6ba711de07986d35ce1f
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Wed Dec 12 19:43:19 2012 +0000

    sna: Pin some batches to avoid CS incoherence on 830/845

the in-kernel w/a of pinning batches was duplicated for older
kernels.

Unfortunately the userspace w/a isn't as good as the kernel one - when
restarting X we need to pin a new set of batch buffer objects. Those
new batches could potentially have stale tlb entries still in the CS,
leading to gpu hangs right after X started.

The other problem is that when support for detecting the kernel-based
w/a added to be able to opt out of it using the EXEC_IS_PINNED in

commit 5b0572503eab235bc7eff20d369241330c41e630
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sun Dec 16 23:04:55 2012 +0000

    sna: Enable support for opting out of the kernel CS workaround

the logic in kgem_create_batch was fumbled: Since we always opt out we
should unconditionally pin the batches. The end result is that we've
ended up with unpinned batches if the kernel implements the w/a :(

Instead of fixing the userspace w/a to work even when the kernel w/a
is available I've opted to just disable the EXEC_IS_PINNED
optimization completely - given the above issues around restarting X
it's imo better to be safe than sorry.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

0 files changed, 0 insertions, 0 deletions