[Intel-gfx] [PATCH 1/2] drm/i915: Remove BLT workaround for pre-production Sandybridge systems.

[Kenneth Graunke]

This code was effectively dead, as < rev08 never shipped.

With the workaround gone, blt_ring_init became just another name for
init_ring_common, so delete it and just call init_ring_common directly.

This patch should not change behavior on Gen6 rev >= 8, nor Gen7.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 drivers/gpu/drm/i915/intel_ringbuffer.c |   55 ++-----------------------------
 1 files changed, 3 insertions(+), 52 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ca70e2f..8198ab3 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1345,66 +1345,17 @@ blt_ring_put_irq(struct intel_ring_buffer *ring)
 			  GEN6_BLITTER_USER_INTERRUPT);
 }
 
-
-/* Workaround for some stepping of SNB,
- * each time when BLT engine ring tail moved,
- * the first command in the ring to be parsed
- * should be MI_BATCH_BUFFER_START
- */
-#define NEED_BLT_WORKAROUND(dev) \
-	(IS_GEN6(dev) && (dev->pdev->revision < 8))
-
-static inline struct drm_i915_gem_object *
-to_blt_workaround(struct intel_ring_buffer *ring)
-{
-	return ring->private;
-}
-
-static int blt_ring_init(struct intel_ring_buffer *ring)
-{
-	if (NEED_BLT_WORKAROUND(ring->dev)) {
-		struct drm_i915_gem_object *obj;
-		u32 *ptr;
-		int ret;
-
-		obj = i915_gem_alloc_object(ring->dev, 4096);
-		if (obj == NULL)
-			return -ENOMEM;
-
-		ret = i915_gem_object_pin(obj, 4096, true);
-		if (ret) {
-			drm_gem_object_unreference(&obj->base);
-			return ret;
-		}
-
-		ptr = kmap(obj->pages[0]);
-		*ptr++ = MI_BATCH_BUFFER_END;
-		*ptr++ = MI_NOOP;
-		kunmap(obj->pages[0]);
-
-		ret = i915_gem_object_set_to_gtt_domain(obj, false);
-		if (ret) {
-			i915_gem_object_unpin(obj);
-			drm_gem_object_unreference(&obj->base);
-			return ret;
-		}
-
-		ring->private = obj;
-	}
-
-	return init_ring_common(ring);
-}
-
 static int blt_ring_begin(struct intel_ring_buffer *ring,
 			  int num_dwords)
 {
 	if (ring->private) {
+		struct drm_i915_gem_object *obj = ring->private;
 		int ret = intel_ring_begin(ring, num_dwords+2);
 		if (ret)
 			return ret;
 
 		intel_ring_emit(ring, MI_BATCH_BUFFER_START);
-		intel_ring_emit(ring, to_blt_workaround(ring)->gtt_offset);
+		intel_ring_emit(ring, obj->gtt_offset);
 
 		return 0;
 	} else
@@ -1447,7 +1398,7 @@ static const struct intel_ring_buffer gen6_blt_ring = {
 	.id			= RING_BLT,
 	.mmio_base		= BLT_RING_BASE,
 	.size			= 32 * PAGE_SIZE,
-	.init			= blt_ring_init,
+	.init			= init_ring_common,
 	.write_tail		= ring_write_tail,
 	.flush			= blt_ring_flush,
 	.add_request		= gen6_add_request,
-- 
1.7.7.1