drm/i915: Clarify the semantics of tiling_changed
Rename obj->tiling_changed to obj->fence_dirty so that it is clear that
it flags when the parameters for an active fence (including the
no-fence) register are changed.
Also, do not set this flag when the object does not have a fence
register allocated currently and the gpu does not depend upon the
unfence. This case works exactly like when a tiled object lost its
fence and hence does not need additional handling for the tiling
change in the code.
v2: Use fence_dirty to better express what the flag tracks and add a few
more details to the comments to serve as a reminder of how the GPU also
uses the unfenced register slot.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Add some bikeshed to the commit message about the stricter
use of fence_dirty.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4cbc45f..faea1b6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -869,7 +869,14 @@
* Current tiling mode for the object.
*/
unsigned int tiling_mode:2;
- unsigned int tiling_changed:1;
+ /**
+ * Whether the tiling parameters for the currently associated fence
+ * register have changed. Note that for the purposes of tracking
+ * tiling changes we also treat the unfenced register, the register
+ * slot that the object occupies whilst it executes a fenced
+ * command (such as BLT on gen2/3), as a "fence".
+ */
+ unsigned int fence_dirty:1;
/** How many users have pinned this object in GTT space. The following
* users can each hold at most one reference: pwrite/pread, pin_ioctl