When my Dell XPS 15 9570 laptop is on, the monitor plugged in the HDMI port is correctly detected. Unplugging the 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 after resuming.
That means that the resolution of the previously plugged monitor is kept, causing "not supported resolution" on the new monitor if the monitors expect different resolutions. 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
This keeps happening with newer BIOS and Kernel:
- Debian 11 (bullseye)
- Linux 5.2.0-3
- Wayland client 1.17, Gnome 3.30
- newest Dell XPS BIOS: 1.13.0