drm: add option to force writeback off.
In order to get some better debugging from people about certain hangs/crashes
we need to be able to turn AGP writeback off permanently...
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/radeon_cp.c b/drivers/char/drm/radeon_cp.c
index 447bfbe..e64d680 100644
--- a/drivers/char/drm/radeon_cp.c
+++ b/drivers/char/drm/radeon_cp.c
@@ -1205,6 +1205,10 @@
dev_priv->writeback_works = 0;
DRM_DEBUG("writeback test failed\n");
}
+ if (radeon_no_wb == 1) {
+ dev_priv->writeback_works = 0;
+ DRM_DEBUG("writeback forced off\n");
+ }
dev_priv->sarea_priv->last_frame = dev_priv->scratch[0] = 0;
RADEON_WRITE(RADEON_LAST_FRAME_REG, dev_priv->sarea_priv->last_frame);
