[PATCH RESEND] drm/rockchip: cdn-dp: add missing check in cdn_dp_config_video()

[Sergey Shtylyov]

The result of cdn_dp_reg_write() is checked everywhere (with the error
being logged by the callers) except one place in cdn_dp_config_video().
Add the missing result check, bailing out early on error...

Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.

Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for rk3399")
Signed-off-by: Sergey Shtylyov <s.shtylyov at auroraos.dev>
Cc: stable at vger.kernel.org
---
Either we need to add the check or drop the assignment to the ret variable
as the value gets ignored anyway...

The patch is against the drm-misc-fixes branch of the DRM kernel.git repo
on gitlab.freedesktop.org.

 drivers/gpu/drm/rockchip/cdn-dp-reg.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
index 0dc3804051a9..9b82b27770e5 100644
--- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c
+++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c
@@ -685,6 +685,8 @@ int cdn_dp_config_video(struct cdn_dp_device *dp)
 	val = div_u64(8 * (symbol + 1), bit_per_pix) - val;
 	val += 2;
 	ret = cdn_dp_reg_write(dp, DP_VC_TABLE(15), val);
+	if (ret)
+		goto err_config_video;
 
 	switch (video->color_depth) {
 	case 6:
-- 
2.52.0