Since we are not concerned with userspace racing itself with set-tiling
(the order is indeterminant even if we take a lock), then we can safely
read back the single obj->tiling_mode and do the static lookup of
swizzle mode without having to take a lock.
get-tiling is reasonably frequent due to the back-channel passing around
of tiling parameters in DRI2/DRI3.
Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_gem_tiling.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c
b/drivers/gpu/drm/i915/i915_gem_tiling.c
index c7588135a82d..387246f19ce2 100644
--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -301,10 +301,8 @@ i915_gem_get_tiling(struct drm_device *dev, void *data,
if (&obj->base == NULL)
return -ENOENT;
- mutex_lock(&dev->struct_mutex);
-
args->tiling_mode = obj->tiling_mode;
- switch (obj->tiling_mode) {
+ switch (args->tiling_mode) {
case I915_TILING_X:
args->swizzle_mode = dev_priv->mm.bit_6_swizzle_x;
break;
@@ -328,8 +326,6 @@ i915_gem_get_tiling(struct drm_device *dev, void *data,
if (args->swizzle_mode == I915_BIT_6_SWIZZLE_9_10_17)
args->swizzle_mode = I915_BIT_6_SWIZZLE_9_10;
- drm_gem_object_unreference(&obj->base);
- mutex_unlock(&dev->struct_mutex);
-
+ drm_gem_object_unreference_unlocked(&obj->base);
return 0;
}
--
2.7.0.rc3
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