drm/i915/dp: Be smarter about connection sense for branch devices
drm/i915/dp: Be smarter about connection sense for branch devices

If there's no downstream device, DPCD success is good enough.  If
there's a hotplug-capable downstream device, count the number of
connected sinks in DP_SINK_STATUS and return success if it's non-zero.
Otherwise, probe DDC and report appropriately.

v2: Check DP_SINK_STATUS instead of something unrelated to sink status.

Tested-by: Takashi Iwai <4596b3305151c7ee743192a95d394341e3d3b644@suse.de>
Signed-off-by: Adam Jackson <4482611cc290c2ce1399431891dcb9221c95f994@redhat.com>
Reviewed-by: Jani Nikula <ba783f3beccaedfda693f41a15407d612a629408@intel.com>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs