drm/rcar-du: Fix buffer pitch alignment

The DU requires a 16 pixels pitch alignement. Make sure dumb buffers are
allocated with the correct pitch, and validate the pitch when creating
frame buffers.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 22 insertions, 2 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index 003b34ee38e3..ff82877de876 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -251,7 +251,7 @@ static struct drm_driver rcar_du_driver = {
         .prime_fd_to_handle     = drm_gem_prime_fd_to_handle,
         .gem_prime_import       = drm_gem_cma_dmabuf_import,
         .gem_prime_export       = drm_gem_cma_dmabuf_export,
-        .dumb_create            = drm_gem_cma_dumb_create,
+        .dumb_create            = rcar_du_dumb_create,
         .dumb_map_offset        = drm_gem_cma_dumb_map_offset,
         .dumb_destroy           = drm_gem_cma_dumb_destroy,
         .fops                   = &rcar_du_fops,
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 06cacf6532c0..d30c2e29bee2 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -138,11 +138,25 @@ void rcar_du_encoder_mode_commit(struct drm_encoder *encoder)
  * Frame buffer
  */
 
+int rcar_du_dumb_create(struct drm_file *file, struct drm_device *dev,
+                        struct drm_mode_create_dumb *args)
+{
+        unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+        unsigned int align;
+
+        /* The pitch must be aligned to a 16 pixels boundary. */
+        align = 16 * args->bpp / 8;
+        args->pitch = roundup(max(args->pitch, min_pitch), align);
+
+        return drm_gem_cma_dumb_create(file, dev, args);
+}
+
 static struct drm_framebuffer *
 rcar_du_fb_create(struct drm_device *dev, struct drm_file *file_priv,
                   struct drm_mode_fb_cmd2 *mode_cmd)
 {
         const struct rcar_du_format_info *format;
+        unsigned int align;
 
         format = rcar_du_format_info(mode_cmd->pixel_format);
         if (format == NULL) {
@@ -151,7 +165,10 @@ rcar_du_fb_create(struct drm_device *dev, struct drm_file *file_priv,
                 return ERR_PTR(-EINVAL);
         }
 
-        if (mode_cmd->pitches[0] & 15 || mode_cmd->pitches[0] >= 8192) {
+        align = 16 * format->bpp / 8;
+
+        if (mode_cmd->pitches[0] & (align - 1) ||
+            mode_cmd->pitches[0] >= 8192) {
                 dev_dbg(dev->dev, "invalid pitch value %u\n",
                         mode_cmd->pitches[0]);
                 return ERR_PTR(-EINVAL);
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.h b/drivers/gpu/drm/rcar-du/rcar_du_kms.h
index e4d8db069a06..dba472263486 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.h
@@ -56,4 +56,7 @@ void rcar_du_encoder_mode_commit(struct drm_encoder *encoder);
 
 int rcar_du_modeset_init(struct rcar_du_device *rcdu);
 
+int rcar_du_dumb_create(struct drm_file *file, struct drm_device *dev,
+                        struct drm_mode_create_dumb *args);
+
 #endif /* __RCAR_DU_KMS_H__ */