On Fri, 28 Jun 2024, Ben Kao <ben.kao@xxxxxxxxx> wrote: > We found that the external monitor would be failed to display > when hot-plug with dual Type-C USB cable on Dell WD19DC dock. > Due to the host would receive 2 lanes setting when the first HPD, > then receive 4 lanes setting later, but the host only sets 2 lanes > DP and skips to set 4 lanes DP. I modify DP lane count if the > current DP lane count is not the same as DPCD reading. > > Signed-off-by: Ben Kao <ben.kao@xxxxxxxxx> Please file a bug according to [1]. BR, Jani. [1] https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html > --- > drivers/gpu/drm/i915/display/intel_dp.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > index 5b3b6ae1e3d7..a9b9023c6744 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp.c > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > @@ -5545,6 +5545,12 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp) > if (!intel_dp_get_dpcd(intel_dp)) > return connector_status_disconnected; > > + /* lanes count changed */ > + if (intel_dp->lane_count != drm_dp_max_lane_count(intel_dp->dpcd)) { > + intel_dp->lane_count = drm_dp_max_lane_count(intel_dp->dpcd); > + return connector_status_disconnected; > + } > + > intel_dp->mst_detect = intel_dp_mst_detect(intel_dp); > > /* if there's no downstream port, we're done */ -- Jani Nikula, Intel
