From: Philip Chen philipchen@chromium.org

[ Upstream commit cd92cc187c053ab010a1570e2d61d68394a5c725 ]

If "data_lanes" property of the dsi output endpoint is missing in the DT, num_data_lanes would be 0 by default, which could cause dsi_host_attach() to fail if dsi->lanes is set to a non-zero value by the bridge driver.

According to the binding document of msm dsi controller, the input/output endpoint of the controller is expected to have 4 lanes. So let's set num_data_lanes to 4 by default.

Signed-off-by: Philip Chen philipchen@chromium.org Reviewed-by: Douglas Anderson dianders@chromium.org Reviewed-by: Stephen Boyd swboyd@chromium.org Link: https://lore.kernel.org/r/20211030100812.1.I6cd9af36b723fed277d34539d3b2ba4c... Signed-off-by: Rob Clark robdclark@chromium.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/dsi/dsi_host.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 77dae147caf90..9abfb19ea7ede 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1677,6 +1677,8 @@ static int dsi_host_parse_lane_data(struct msm_dsi_host *msm_host, if (!prop) { dev_dbg(dev, "failed to find data lane mapping, using default\n"); + /* Set the number of date lanes to 4 by default. */ + msm_host->num_data_lanes = 4; return 0; }