| Message ID | 20190718145407.21352-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] drm/i915: Drop wmb() inside pread_gtt | expand |
On Thu, Jul 18, 2019 at 03:54:04PM +0100, Chris Wilson wrote: > Inside pread, we only ever read from the GTT so the serialising wmb() > instructions around the GGTT PTE updates are pointless. Hard to argue with that. Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > --- > drivers/gpu/drm/i915/i915_gem.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index a207b90924e4..fed0bc421a55 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -395,11 +395,9 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj, > unsigned page_length = PAGE_SIZE - page_offset; > page_length = remain < page_length ? remain : page_length; > if (node.allocated) { > - wmb(); > ggtt->vm.insert_page(&ggtt->vm, > i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT), > node.start, I915_CACHE_NONE, 0); > - wmb(); > } else { > page_base += offset & PAGE_MASK; > } > @@ -419,7 +417,6 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj, > out_unpin: > mutex_lock(&i915->drm.struct_mutex); > if (node.allocated) { > - wmb(); > ggtt->vm.clear_range(&ggtt->vm, node.start, node.size); > remove_mappable_node(&node); > } else { > -- > 2.22.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index a207b90924e4..fed0bc421a55 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -395,11 +395,9 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj, unsigned page_length = PAGE_SIZE - page_offset; page_length = remain < page_length ? remain : page_length; if (node.allocated) { - wmb(); ggtt->vm.insert_page(&ggtt->vm, i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT), node.start, I915_CACHE_NONE, 0); - wmb(); } else { page_base += offset & PAGE_MASK; } @@ -419,7 +417,6 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj, out_unpin: mutex_lock(&i915->drm.struct_mutex); if (node.allocated) { - wmb(); ggtt->vm.clear_range(&ggtt->vm, node.start, node.size); remove_mappable_node(&node); } else {
Inside pread, we only ever read from the GTT so the serialising wmb() instructions around the GGTT PTE updates are pointless. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/i915_gem.c | 3 --- 1 file changed, 3 deletions(-)