[PATCH 1/3] drm/radeon: Use write-combined CPU mappings of ring buffers with PCIe

[Michel Dänzer]

From: Michel D?nzer <michel.daen...@amd.com>

PCI GART doesn't support unsnooped access. AGP GART already uses
write-combined CPU mappings.

Signed-off-by: Michel D?nzer <michel.daenzer at amd.com>
---
 drivers/gpu/drm/radeon/radeon_ring.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_ring.c 
b/drivers/gpu/drm/radeon/radeon_ring.c
index 71439f0..7cfea7e 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -640,7 +640,9 @@ int radeon_ring_init(struct radeon_device *rdev, struct 
radeon_ring *ring, unsig
        /* Allocate ring buffer */
        if (ring->ring_obj == NULL) {
                r = radeon_bo_create(rdev, ring->ring_size, PAGE_SIZE, true,
-                                    RADEON_GEM_DOMAIN_GTT, 0,
+                                    RADEON_GEM_DOMAIN_GTT,
+                                    (rdev->flags & RADEON_IS_PCIE) ?
+                                    RADEON_GEM_GTT_WC : 0,
                                     NULL, &ring->ring_obj);
                if (r) {
                        dev_err(rdev->dev, "(%d) ring create failed\n", r);
-- 
2.0.1