https://bugs.freedesktop.org/show_bug.cgi?id=41561
--- Comment #2 from Simon Farnsworth simon.farnsworth@onelan.co.uk 2011-10-07 09:07:40 PDT --- drm_helper_hpd_irq_event() isn't generating uevents, because connector->status is not being updated somewhere, and is remaining at connector_status_connected, when it should be being updated to connector_status_disconnected.
If I do cat /sys/class/drm/card0-HDMI-A-1/status, I see the status is "disconnected", but something resets it by the time the helper comes back round. Possibly connected to the following from dmesg:
# cat /sys/class/drm/card0-HDMI-A-1/status ; dmesg -c [16791.042128] [drm:radeon_atombios_connected_scratch_regs], DFP1 disconnected
# sleep 10 ; dmesg -c [16799.522394] [drm:radeon_atombios_connected_scratch_regs], DFP1 connected [16799.522407] [drm:output_poll_execute], [CONNECTOR:15:HDMI-A-1] status updated from 1 to 1 [16799.524465] [drm:output_poll_execute], [CONNECTOR:17:VGA-1] status updated from 2 to 2