Using kernel 4.1 on a thinkpad X240, I get the following after resuming from suspend: $ cat /sys/class/drm/card0/*/status unknown unknown unknown unknown unknown If at this point I just run the xrandr CLI tool, then I get correct values again: $ cat /sys/class/drm/card0/*/status disconnected disconnected connected disconnected disconnected I also found out that with kernel 4.0 I don't get the 'unknown' statuses on the /sys connector files after resuming but nonetheless the X server doesn't seem to get notified about newly connected ports (while suspended) until a forced refresh with 'xrandr' is done.
This was already being tracked in the kernel bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=100641
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