+static void r420_cp_errata_init(struct radeon_device *rdev)
+{
+ /* RV410 and R420 can lock up if CP DMA to host memory happens
+ * while the 2D engine is busy.
+ *
+ * The proper workaround is to queue a RESYNC at the beginning
+ * of the CP init, apparently.
+ */
+ radeon_scratch_get(rdev, &rdev->config.r300.resync_scratch);
+ radeon_ring_lock(rdev, 8);
+ radeon_ring_write(rdev, PACKET0(R300_CP_RESYNC_ADDR, 1));
+ radeon_ring_write(rdev, rdev->config.r300.resync_scratch);
+ radeon_ring_write(rdev, 0xDEADBEEF);
+ radeon_ring_unlock_commit(rdev);
+}
+
+static void r420_cp_errata_fini(struct radeon_device *rdev)
+{
+ /* Catch the RESYNC we dispatched all the way back,
+ * at the very beginning of the CP init.
+ */
+ radeon_ring_lock(rdev, 8);
+ radeon_ring_write(rdev, PACKET0(R300_RB3D_DSTCACHE_CTLSTAT, 0));
+ radeon_ring_write(rdev, R300_RB3D_DC_FINISH);
+ radeon_ring_unlock_commit(rdev);
+ radeon_scratch_free(rdev, rdev->config.r300.resync_scratch);
+}
+