@Francis: This is another bug and you should open another bug report for that one.
That being said, I think I haven't seen that one using the Wily kernel (yet). But I have seen one, that is probably the same bug, using newer kernels (4.4/4.5). I have reported the bug against the 4.5.0 kernel on freedesktop.org. In my case the 4.5.0 kernel also crashed in drm_dp_payload_send_msg, but got there via the intel_mst_post_disable_dp call, instead of intel_mst_enable_dp call like in your case, but I think both crashes probably have the same root cause.
One of the developers, Chris Wilson, raised the bug priority to highest/blocker, so I hope this will get fixed soon, but there are no patches to test yet.
@Francis: This is another bug and you should open another bug report for that one.
That being said, I think I haven't seen that one using the Wily kernel (yet). But I have seen one, that is probably the same bug, using newer kernels (4.4/4.5). I have reported the bug against the 4.5.0 kernel on freedesktop.org. In my case the 4.5.0 kernel also crashed in drm_dp_ payload_ send_msg, but got there via the intel_mst_ post_disable_ dp call, instead of intel_mst_enable_dp call like in your case, but I think both crashes probably have the same root cause.
I have reported it here: https:/ /bugs.freedeskt op.org/ show_bug. cgi?id= 94534
One of the developers, Chris Wilson, raised the bug priority to highest/blocker, so I hope this will get fixed soon, but there are no patches to test yet.