From: Benoit Parrot <bparrot@ti.com>
Date: Wed, 22 Jun 2016 12:59:50 -0500
Subject: drm/omap: dispc: disp_wb_setup to check return code
Git-commit: b5d025eff5206300be0f59bfe10c5b9e1c895af4
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

When dispc_wb_setup() calls dispc_ovl_setup_common() it does not
check for failure but instead keeps on partially setting up WB.
This causes the WB H/W to be partially initialized and yield
unexpected behavior.

Make sure return code is successful before proceeding.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/omapdrm/dss/dispc.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/omapdrm/dss/dispc.c
+++ b/drivers/gpu/drm/omapdrm/dss/dispc.c
@@ -2783,6 +2783,8 @@ int dispc_wb_setup(struct dispc_device *
 		wi->height, wi->fourcc, wi->rotation, zorder,
 		wi->pre_mult_alpha, global_alpha, wi->rotation_type,
 		replication, vm, mem_to_mem);
+	if (r)
+		return r;
 
 	switch (wi->fourcc) {
 	case DRM_FORMAT_RGB565:
@@ -2823,7 +2825,7 @@ int dispc_wb_setup(struct dispc_device *
 		REG_FLD_MOD(dispc, DISPC_OVL_ATTRIBUTES2(plane), wbdelay, 7, 0);
 	}
 
-	return r;
+	return 0;
 }
 
 static int dispc_ovl_enable(struct dispc_device *dispc,