Call drm_mode_size_dumb() to compute dumb-buffer scanline pitch and
buffer size. Align the pitch according to hardware requirements.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/gpu/drm/xlnx/zynqmp_kms.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_kms.c b/drivers/gpu/drm/xlnx/zynqmp_kms.c
index b47463473472..7ea0cd4f71d3 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_kms.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_kms.c

@@ -19,6 +19,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
+#include <drm/drm_dumb_buffers.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_fbdev_dma.h>
 #include <drm/drm_fourcc.h>

@@ -363,10 +364,12 @@ static int zynqmp_dpsub_dumb_create(struct drm_file *file_priv,
 				    struct drm_mode_create_dumb *args)
 {
 	struct zynqmp_dpsub *dpsub = to_zynqmp_dpsub(drm);
-	unsigned int pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+	int ret;
 
 	/* Enforce the alignment constraints of the DMA engine. */
-	args->pitch = ALIGN(pitch, dpsub->dma_align);
+	ret = drm_mode_size_dumb(drm, args, dpsub->dma_align, 0);
+	if (ret)
+		return ret;
 
 	return drm_gem_dma_dumb_create_internal(file_priv, drm, args);
 }