Quoting Philip Chen (2021-10-29 15:27:41)

MSM DSI host driver actually parses "data-lanes" in DT and compare
it with the number of DSI lanes the bridge driver sets for
mipi_dsi_device. So we need to always specify "data-lanes" for the
DSI host output. As of now, "data-lanes" is added to ti-sn65dsi86 dts
fragment, but missing in parade-ps8640 dts fragment, which requires
a fixup.

I don't see data-lanes required in the schema, and
dsi_host_parse_lane_data() seems happy to continue without it. I do see
that num_data_lanes isn't set though. Does this patch fix it?

----8<----

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c

b/drivers/gpu/drm/msm/dsi/dsi_host.c
index e269df285136..f6fba07220e5 100644

--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c

@@ -1696,6 +1696,7 @@ static int dsi_host_parse_lane_data(struct

msm_dsi_host *msm_host,
 	if (!prop) {
 		DRM_DEV_DEBUG(dev,
 			"failed to find data lane mapping, using default\n");
+		msm_host->num_data_lanes = 4;
 		return 0;
 	}