> On Fri, 28 Jun 2024, Ben Kao <ben....@intel.com> 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....@intel.com>
>
> Please file a bug according to [1].
>
> BR,
> Jani.
>
> [1] https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html
This patch is for the bug number 11195
https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11195
>
>
> > ---
> > 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
