[Intel-gfx] [PATCH v3 16/23] drm/i915: Remove superfluous posting reads after clear GGTT

[Chris Wilson]

The barrier here is not required - we apply the barrier before the range
is ever reused by the GPU instead.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 1cb3f486a170..c59088b1004e 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2183,7 +2183,6 @@ static void gen8_ggtt_clear_range(struct i915_address_space *vm,
 
 	for (i = 0; i < num_entries; i++)
 		gen8_set_pte(&gtt_base[i], scratch_pte);
-	readl(gtt_base);
 }
 
 static void gen6_ggtt_clear_range(struct i915_address_space *vm,
@@ -2208,7 +2207,6 @@ static void gen6_ggtt_clear_range(struct i915_address_space *vm,
 
 	for (i = 0; i < num_entries; i++)
 		iowrite32(scratch_pte, &gtt_base[i]);
-	readl(gtt_base);
 }
 
 static void i915_ggtt_insert_page(struct i915_address_space *vm,
@@ -2232,7 +2230,6 @@ static void i915_ggtt_insert_entries(struct i915_address_space *vm,
 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
 
 	intel_gtt_insert_sg_entries(pages, start >> PAGE_SHIFT, flags);
-
 }
 
 static void i915_ggtt_clear_range(struct i915_address_space *vm,
-- 
2.11.0