drm/fsl-dcu: do not transfer registers on plane init

There is no need to explicitly initiate a register transfer and
turn off the DCU after initializing the plane registers. In fact,
this is harmful and leads to unnecessary flickers if the DCU has
been left on by the bootloader.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Tested-By: Meng Yi <meng.yi@nxp.com>

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
index a7e5486bd1e934be88374df0ce08731f6286ee1a..9e6f7d8112b32f87e2d34657918589c5ffdfab57 100644 (file)
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
@@ -211,11 +211,6 @@ void fsl_dcu_drm_init_planes(struct drm_device *dev)
                for (j = 1; j <= fsl_dev->soc->layer_regs; j++)
                        regmap_write(fsl_dev->regmap, DCU_CTRLDESCLN(i, j), 0);
        }
-       regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE,
-                          DCU_MODE_DCU_MODE_MASK,
-                          DCU_MODE_DCU_MODE(DCU_MODE_OFF));
-       regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE,
-                    DCU_UPDATE_MODE_READREG);
 }
 
 struct drm_plane *fsl_dcu_drm_primary_create_plane(struct drm_device *dev)