When my Dell XPS 15 9570 laptop is on, the monitors plugged in the HDMI port are correctly detected. Unplugging a monitor also works as expected.
However, when waking up from suspend by briefly lifting the lid open, the HDMI port is not reconfigured. Whatever was plugged at the time it was suspended is still considered connected on resume.
Moreover, the resolution of a previously plugged monitor is kept, causing "not supported resolution" if a monitor with a smaller resolution was plugged before resuming. Re-connecting the new monitor fixes the issue in this case.
I have not figured out exactly how, but leaving the lid open when suspended or after resuming seems to change this behavior.
How can I force the HDMI ports to be scanned again on resume? or otherwise work around this annoying issue.
Some more context:
- Dual GPU, integrated Intel UHD 630 in use (i915)
- Discrete nvidia GPU disabled, no proprietary drivers loaded
- Debian 10 (buster)
- Linux 4.19.0-2:
nouveau.runpm=0 acpi_rev_override=1 acpi_osi=Linux nouveau.modeset=0 scsi_mod.use_blk_mq=1 mem_sleep_default=deep
- Wayland 1.16, Gnome 3.30