Sure, the monitor goes away when the screen gets locked. Tried deleting monitors.xml, no change.
The HDMI port on the laptop works just fine. The cable works just fine. It fails when the screen gets locked, and as I have just discovered, on boot. Seems like something is failing in the process of waking up the monitor. If I detach the HDMI cable and attach it again, the image appears. If I power off the monitor and power it on again while attached, it fails, with the monitor detecting no signal. So, to recap, clearly there is a failure in the mechanism in charge of signaling to the monitor to power on, or in the negotiation process immediately after. El 17/12/25 a les 4:19, Daniel van Vugt ha escrit: > Thanks. There seems to be a recurring issue with a monitor vanishing > from the known list of monitors: > > de des. 16 10:44:51 laptop-dani-g gnome-shell[4343]: > (../src/backends/meta-output.c:142):meta_output_get_monitor: runtime check > failed: (priv->monitor) > de des. 16 10:44:51 laptop-dani-g gnome-shell[4343]: > (../src/backends/meta-output.c:142):meta_output_get_monitor: runtime check > failed: (priv->monitor) > ... > de des. 16 10:44:57 laptop-dani-g gnome-shell[4343]: > (../src/backends/meta-output.c:142):meta_output_get_monitor: runtime check > failed: (priv->monitor) > de des. 16 10:44:57 laptop-dani-g gnome-shell[4343]: > meta_monitor_manager_get_logical_monitor_from_number: assertion '(unsigned > int) number < g_list_length (manager->logical_monitors)' failed > de des. 16 10:44:57 laptop-dani-g gnome-shell[4343]: > meta_workspace_get_work_area_for_monitor: assertion 'logical_monitor != NULL' > failed > de des. 16 10:44:57 laptop-dani-g gnome-shell[4343]: > meta_monitor_manager_get_logical_monitor_from_number: assertion '(unsigned > int) number < g_list_length (manager->logical_monitors)' failed > de des. 16 10:44:57 laptop-dani-g gnome-shell[4343]: > meta_workspace_get_work_area_for_monitor: assertion 'logical_monitor != NULL' > failed > > Although some of that I would say is undeniably a bug in Mutter (the > compositor), because it should be tracking monitors with less confusing > messages, what triggers it might be lower level. Lower level like the > kernel or hardware is reporting the monitor as disconnected. > > The first thing I would try is to delete the monitor config > (~/.config/monitors.xml) and log in again. Just in case the cause is > some weird configuration and resetting to defaults avoids it. > > If that doesn't solve the problem then next I would try a new display > cable, because those are often the issue: > https://discourse.ubuntu.com/t/the-display-bug-we-cant-fix/57434 > > Avoiding HDMI completely is also advisable if you can get a USB-C to > whatever adapter cable. This is because laptops often have cheap low > quality HDMI ports and running the display signal though the USB-C port > in Alt mode avoids that. > > -- <https://www.robsurgical.com> Daniel Guerrero Miralles Software Team Lead [email protected] Aquest missatge pot contenir informació confidencial i/o privilegiada. Si no sou el destinatari, si us plau informeu al remitent i elimineu el missatge. Este mensaje puede contener información confidencial y/o privilegiada. Si no es el destinatario, por favor informe al remitente y elimine el mensaje. This message may contain confidential and/or privileged information. If you are not the addressee, please notify the sender and delete the message. ** Attachment added: "KqJLDhKDbuZ3FEkJ.png" https://bugs.launchpad.net/bugs/2136133/+attachment/5934281/+files/KqJLDhKDbuZ3FEkJ.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2136133 Title: [i915] External screen black after sleep To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2136133/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
