linux/drivers/gpu
Chris Wilson 4b6d846e9a drm/i915: Drop the overzealous warning from i915_gem_set_cache_level
By our earlier reckoning, move from a snooped/llc setting to an uncached
setting, leaves the CPU cache in a consistent state irrespective of our
domain tracking - so we can forgo the warning about the lack of
invalidation. Similarly for any writes posted to the snooped CPU domain,
we know will be safely clflushed to the uncached PTEs after forcing the
domain change.

This WARN started to pop up with

commit d46f1c3f13
Author:     Chris Wilson <chris@chris-wilson.co.uk>
AuthorDate: Thu Aug 8 14:41:06 2013 +0100

    drm/i915: Allow the GPU to cache stolen memory

Ville brought up a scenario where the interaction of a set_caching
ioctl call from userspace on a scanout buffer (i.e. obj->pin_display
is set) resulted in the code getting confused and not properly
flushing stale cpu cachelines. Luckily we already prevent this by
rejecting caching changes when obj->pin_count is set.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68040
Tested-by: cancan,feng <cancan.feng@intel.com>
[danvet: Add buglink, bisect result and explain why Ville's scenario
is already taken care of.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-08-22 13:31:46 +02:00
..
drm drm/i915: Drop the overzealous warning from i915_gem_set_cache_level 2013-08-22 13:31:46 +02:00
host1x gpu: host1x: Rework CPU syncpoint increment 2013-06-22 12:43:55 +02:00
vga fbcon: fix locking harder 2013-02-08 12:02:43 +10:00
Makefile gpu: host1x: Add host1x driver 2013-04-22 12:32:40 +02:00