Quoting Kuogee Hsieh (2021-04-13 16:11:10)
> Link status is different from display connected status in the case
> of something like an Apple dongle where the type-c plug can be
> connected, and therefore the link is connected, but no sink is
> connected until an HDMI cable is plugged into the dongle.
> The sink_count of DPCD of dongle will increase to 1 once an HDMI
> cable is plugged into the dongle so that display connected status
> will become true. This checking also apply at pm_resume.
>
> Fixes: 94e58e2d06e3 ("drm/msm/dp: reset dp controller only at boot up and
> pm_resume")
> Reported-by: Stephen Boyd <[email protected]>
> Signed-off-by: Kuogee Hsieh <[email protected]>
> ---
Reviewed-by: Stephen Boyd <[email protected]>
Tested-by: Stephen Boyd <[email protected]>