** Description changed: - The last system update to 24.04 totally stuffed the K5000M display - adapter configuration. + Revised this bug description now that I have nailed down what the + problem is.... - With 24.04 set to use M5000M (ext screen) as my primary display it - doesn't see the ext screen for GUI use so defaults to the internal Intel - graphics adapter. The M5000M video output is not configured correctly at - all. The screen is 99% white with a hint of a Ubuntu top of screen - status bar showing. (see attached photo). + My setup - Dell M6700 laptop running on a E-Port II docking station with external USB keyboard and IIYama DP widescreen monitor set to 100hz 3440x1440 resolution plugged into M5000M output via the laptops DP 1.2 port. + Important Note -- This monitor only works using 100hz or less refresh rate otherwise it shows mostly black screen with grey banding. - Sometimes the display is top 30% all white and the rest black. + Problem - At Ubuntu logon, the system drives the external monitor at its + maximum refresh rate. After logon has completed, the monitor is then + driven at the user defined settings for the monitor. - In one case the sync rate setting was incorrect but changing it back to - 100Hz failed to solve the issue. + The reason the monitor doesn't work at the max refresh rate is because + my laptops DP port is version 1.2 which can't handle the data rate at + the top refresh rate for the monitor. - This new bug is in addition to the suspend\hibernation problem when - starting up 24.04 with the laptop lid shut. In this instance I normally - lift the lid slightly to get the laptop to wake up again and upon - closing the lid I used to get the Ubuntu GUI displayed on the ext - monitor. This behavior no longer occurs, i.e. the ext monitor ends up - black or white as described above. Sometimes even the laptop internal - graphics adapter shows a totally black screen as well. + To replicate this fault your test platform will need to use a DP1.2 port + for the external monitor connection. Ubuntu needs to know that the max + refresh rate it can use for the monitor is limited by the top rate DP + 1.2 can handle. - In one case I had to totally power down my ext monitor because it had - got so screwed up by 24.04 that even if I booted into Windows 10, Win10 - failed to detect\use the external monitor connected tot the M5000M. + See photo in next comment for what the external monitor screen looks + like when the laptop DP 1.2 connection is over-driven - Dell M6700 laptop running on a E-Port II docking station with ext USB - keyboard and IIYama DP widescreen monitor set to 100hx 3440x1440 - resolution plugged into M5000M output via a DP 1.2 cable. - - Ubuntu 22.04.5 LTS works perfectly on my hardware setup. - - Attached photos of the external monitor screen display. + Note Ubuntu 22.04.5 LTS did not do this behavior. It worked perfectly on + my hardware setup.
** Description changed: Revised this bug description now that I have nailed down what the problem is.... My setup - Dell M6700 laptop running on a E-Port II docking station with external USB keyboard and IIYama DP widescreen monitor set to 100hz 3440x1440 resolution plugged into M5000M output via the laptops DP 1.2 port. Important Note -- This monitor only works using 100hz or less refresh rate otherwise it shows mostly black screen with grey banding. Problem - At Ubuntu logon, the system drives the external monitor at its maximum refresh rate. After logon has completed, the monitor is then driven at the user defined settings for the monitor. The reason the monitor doesn't work at the max refresh rate is because my laptops DP port is version 1.2 which can't handle the data rate at the top refresh rate for the monitor. To replicate this fault your test platform will need to use a DP1.2 port for the external monitor connection. Ubuntu needs to know that the max refresh rate it can use for the monitor is limited by the top rate DP 1.2 can handle. See photo in next comment for what the external monitor screen looks like when the laptop DP 1.2 connection is over-driven Note Ubuntu 22.04.5 LTS did not do this behavior. It worked perfectly on my hardware setup. + + Secondary Note - this problem also happens if you close the laptop lid, + i.e. the system ignores the user setting max refresh rate to the + external monitor. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2098842 Title: 25.04 Login not using ext monitor settings prevents ext monitor working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kernel-package/+bug/2098842/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
