drm/radeon: fixup radeon_do_engine_reset

Cleanup do engine reset for different chip families.
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/char/drm/radeon_cp.c

@@ -418,12 +418,13 @@ static void radeon_do_cp_stop(drm_radeon_private_t * dev_priv)
 static int radeon_do_engine_reset(struct drm_device * dev)
 {
 	drm_radeon_private_t *dev_priv = dev->dev_private;
-	u32 clock_cntl_index, mclk_cntl, rbbm_soft_reset;
+	u32 clock_cntl_index = 0, mclk_cntl = 0, rbbm_soft_reset;
 	DRM_DEBUG("\n");
 
 	radeon_do_pixcache_flush(dev_priv);
 
-	if ((dev_priv->flags & RADEON_FAMILY_MASK) < CHIP_RV515) {
+	if ((dev_priv->flags & RADEON_FAMILY_MASK) <= CHIP_RV410) {
+		/* may need something similar for newer chips */
 		clock_cntl_index = RADEON_READ(RADEON_CLOCK_CNTL_INDEX);
 		mclk_cntl = RADEON_READ_PLL(dev, RADEON_MCLK_CNTL);
 
@@ -434,6 +435,7 @@ static int radeon_do_engine_reset(struct drm_device * dev)
 						    RADEON_FORCEON_YCLKB |
 						    RADEON_FORCEON_MC |
 						    RADEON_FORCEON_AIC));
+	}
 
 	rbbm_soft_reset = RADEON_READ(RADEON_RBBM_SOFT_RESET);
 
@@ -456,6 +458,7 @@ static int radeon_do_engine_reset(struct drm_device * dev)
 						RADEON_SOFT_RESET_RB)));
 	RADEON_READ(RADEON_RBBM_SOFT_RESET);
 
+	if ((dev_priv->flags & RADEON_FAMILY_MASK) <= CHIP_RV410) {
 		RADEON_WRITE_PLL(RADEON_MCLK_CNTL, mclk_cntl);
 		RADEON_WRITE(RADEON_CLOCK_CNTL_INDEX, clock_cntl_index);
 		RADEON_WRITE(RADEON_RBBM_SOFT_RESET, rbbm_soft_reset);