[PATCH 2/4] drm/fsl-dcu: respect pos/size register sizes

[Stefan Agner]

Mask the size and position values to avoid mutual overwriting.
Especially, a negative X position caused the Y position to be
overwritten with 0xfff too. This has been observed when using
a layer as cursor layer.

Signed-off-by: Stefan Agner <stefan at agner.ch>
---
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
index 3b371fe7..060f881 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
@@ -118,11 +118,11 @@
 
 #define DCU_CTRLDESCLN(layer, reg)	(0x200 + (reg - 1) * 4 + (layer) * 0x40)
 
-#define DCU_LAYER_HEIGHT(x)		((x) << 16)
-#define DCU_LAYER_WIDTH(x)		(x)
+#define DCU_LAYER_HEIGHT(x)		(((x) & 0x7ff) << 16)
+#define DCU_LAYER_WIDTH(x)		((x) & 0x7ff)
 
-#define DCU_LAYER_POSY(x)		((x) << 16)
-#define DCU_LAYER_POSX(x)		(x)
+#define DCU_LAYER_POSY(x)		(((x) & 0xfff) << 16)
+#define DCU_LAYER_POSX(x)		((x) & 0xfff)
 
 #define DCU_LAYER_EN			BIT(31)
 #define DCU_LAYER_TILE_EN		BIT(30)
-- 
2.9.3