drm/radeon: fix HD6790, HD6570 backend programming

commit 95c4b23ec4e2fa5604df229ddf134e31d7b3b378 upstream.

Without this bit sets we get broken rendering and
lockups.

fglrx sets this bit.

Bugs that should be fixed by this patch :
https://bugs.freedesktop.org/show_bug.cgi?id=49792
https://bugzilla.kernel.org/show_bug.cgi?id=43207
https://bugs.freedesktop.org/show_bug.cgi?id=39282

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 31fb3480d9b..8846bad45e6 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -2069,9 +2069,9 @@ static void evergreen_gpu_init(struct radeon_device *rdev)
                 WREG32(CC_SYS_RB_BACKEND_DISABLE, rb);
                 WREG32(GC_USER_RB_BACKEND_DISABLE, rb);
                 WREG32(CC_GC_SHADER_PIPE_CONFIG, sp);
-        }
+        }
 
-        grbm_gfx_index |= SE_BROADCAST_WRITES;
+        grbm_gfx_index = INSTANCE_BROADCAST_WRITES | SE_BROADCAST_WRITES;
         WREG32(GRBM_GFX_INDEX, grbm_gfx_index);
         WREG32(RLC_GFX_INDEX, grbm_gfx_index);