[PATCH v6 4/5] drm/bridge: analogix_dp: Add validation for samsung,lane-count property

[Damon Ding]

Add validity check for samsung,lane-count to ensure DT-provided
lane count values are specification-compliant.

Suggested-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
Signed-off-by: Damon Ding <damon.ding at rock-chips.com>

---

Changes in v5:
- Apply DRM DP helper API to check the validity of DP lane count.

Changes in v6:
- Rebase after the new commit for restoring mandatory properties
  samsung,link-rate and samsung,lane-count.
---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 5240efcd3861..039e076d2b8a 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1270,7 +1270,8 @@ static int analogix_dp_dt_parse_pdata(struct analogix_dp_device *dp)
 			return dev_err_probe(dp->dev, -EINVAL,
 					     "Failed to get samsung,link-rate\n");
 		video_info->max_link_rate = val;
-		if (of_property_read_u32(dp_node, "samsung,lane-count", &val))
+		if (of_property_read_u32(dp_node, "samsung,lane-count", &val) ||
+		    !drm_dp_lane_count_is_valid(val))
 			return dev_err_probe(dp->dev, -EINVAL,
 					     "Failed to get samsung,lane-count\n");
 		video_info->max_lane_count = val;
-- 
2.34.1