drm/radeon/kms/blit: workaround some hw issues on evergreen+

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen_blit_kms.c b/drivers/gpu/drm/radeon/evergreen_blit_kms.c
index ba06a69c6de8..40867290863c 100644
--- a/drivers/gpu/drm/radeon/evergreen_blit_kms.c
+++ b/drivers/gpu/drm/radeon/evergreen_blit_kms.c
@@ -199,6 +199,16 @@ static void
 set_scissors(struct radeon_device *rdev, int x1, int y1,
              int x2, int y2)
 {
+        /* workaround some hw bugs */
+        if (x2 == 0)
+                x1 = 1;
+        if (y2 == 0)
+                y1 = 1;
+        if (rdev->family == CHIP_CAYMAN) {
+                if ((x2 == 1) && (y2 == 1))
+                        x2 = 2;
+        }
+
         radeon_ring_write(rdev, PACKET3(PACKET3_SET_CONTEXT_REG, 2));
         radeon_ring_write(rdev, (PA_SC_SCREEN_SCISSOR_TL - PACKET3_SET_CONTEXT_REG_START) >> 2);
         radeon_ring_write(rdev, (x1 << 0) | (y1 << 16));