The attachment in comment #10 confirms the problem is happening at a low level in the kernel. Although Xorg could override that if it was smart enough. In theory you can do it manually but would need to become an expert at crafting modeline entries to get it working. I don't know how myself. If that's possible then the data you need is in comment #7.
Obviously Windows 10 demonstrates that it is possible to support this monitor with this HDMI port. Only Linux does not yet... As a workaround, if you have a USB-C port and an appropriate cable/adapter then you might be able to use the DisplayPort on the monitor. If that works then it should give different timings and might provide the 4K option... also at 60Hz instead of just 30Hz. ** Changed in: linux (Ubuntu) Status: Incomplete => New ** Changed in: xorg-server (Ubuntu) Status: Incomplete => New -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1890418 Title: i915 does not expose vendor-specific extended HDMI timings/modes Status in linux package in Ubuntu: Incomplete Status in xorg-server package in Ubuntu: New Bug description: I have a Toshiba radius 11 laptop which has a 4 k native screen. I have connected an Asus PB287Q 28" external monitor (https://www.asus.com/us/Commercial-Monitors/PB287Q/specifications/) over HDMI which displays the full 4K resolution when running under windows10 but will only reach a maximum resolution of 1920x1080 under ubuntu 20.04, same hardware just dual booting. Under Monitor Preferences this monitor is detected as an "Ancor Communications inc 28" and the monitor preferences provides a number of resolution steps up to 1920. If I issue "xrandr --addmode HDMI-1 3840x2160" this resolution is added to the monitor preferences pick list but attempting to apply it results in "the selected configuration for displays could not ..." message To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1890418/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp