drm: rcar-du: Simplify and fix probe error handling

It isn't safe to call drm_dev_unregister() without first initializing
mode setting with drm_mode_config_init(). This leads to a crash if
either IO memory can't be remapped or vblank initialization fails.

Fix this by reordering the initialization sequence. Move vblank
initialization after the drm_mode_config_init() call, and move IO
remapping before drm_dev_alloc() to avoid the need to perform clean up
in case of failure.

While at it remove the explicit drm_vblank_cleanup() call from
rcar_du_remove() as the drm_dev_unregister() function already cleans up
vblank.

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

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index d3ab106..184ed7a 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -559,6 +559,13 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 	if (ret < 0)
 		return ret;
 
+	/* Initialize vertical blanking interrupts handling. Start with vblank
+	 * disabled for all CRTCs.
+	 */
+	ret = drm_vblank_init(dev, (1 << rcdu->info->num_crtcs) - 1);
+	if (ret < 0)
+		return ret;
+
 	/* Initialize the groups. */
 	num_groups = DIV_ROUND_UP(rcdu->num_crtcs, 2);