[PATCH 2/2] drm/i915: properly clflush pwrites to phys objects

[Daniel Vetter]

Usually results in (rare) cursor corruptions on platforms
requiring physically addressed cursors.

Note to the stable team: This requires the drm core patch
"drm: add helper to clflush a virtual address range" which
creates the helper used here.

Tested-and-reported-by: Bruno Prémont <bonbons at linux-vserver.org>
Cc: stable at kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35460
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=21442
Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 39459d2..e395a7d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4123,6 +4123,7 @@ i915_gem_phys_pwrite(struct drm_device *dev,
 			return -EFAULT;
 	}
 
+	drm_clflush_virt_range(vaddr, args->size);
 	intel_gtt_chipset_flush();
 	return 0;
 }
-- 
1.7.7.3