From: Alex Deucher alexander.deucher@amd.com

We often end up missing fences on older asics with writeback enabled which leads to delays in the userspace accel code, so just disable it by default on those asics.

Reported-by: Helge Deller deller@gmx.de Reported-by: Dave Airlie airlied@redhat.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org --- drivers/gpu/drm/radeon/radeon_device.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c index 5fcf135..420db65 100644 --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -228,8 +228,11 @@ int radeon_wb_init(struct radeon_device *rdev) if (radeon_no_wb == 1) rdev->wb.enabled = false; else { - /* often unreliable on AGP */ if (rdev->flags & RADEON_IS_AGP) { + /* often unreliable on AGP */ + rdev->wb.enabled = false; + } else if (rdev->family < CHIP_R300) { + /* often unreliable on pre-r300 */ rdev->wb.enabled = false; } else { rdev->wb.enabled = true;