On Tuesday, June 2, 2020 9:38 AM, Pekka Paalanen ppaalanen@gmail.com wrote:
Can it happen that there will be no modes left in the list?
Reading drm_helper_probe_single_connector_modes, this sounds unlikely but possible.
This isn't specific to link-status though. This can be the case on a regular hotplug uevent too.
What if userspace is driving two connectors from the same CRTC, and only one connector gets link-status bad, what does it mean? Is the other connector still running as normal, as if the failed connector didn't even exist?
That is mostly a question about what happens if userspace does not fix up the link-status=bad connector and does not detach it from the CRTC, but keeps on flipping or modesetting as if the failure never happened. I guess I could ask it about both a CRTC that has another connector still good, and a CRTC where the failed connector was the only one.
Can I trust that if the other connector is in any way affected, it too will get link-status bad?
link-status is about link maintenance (e.g. DP link training), so I think the other connector would be fine in this case. I'll add this to the next version and let Daniel/Manasi comment if that's incorrect.