Can no longer use 4k resolution

Hello,

I’m running Fedora 33 on:

Thinkpad T480
Intel UHD Graphics 620
Thinkpad Thunderbolt 3 Dock Gen 2
Iiyama G-Master GB2888UHSU 4k Monitor

Linux localhost.localdomain 5.9.16-200.fc33.x86_64 #1 SMP Mon Dec 21 14:08:22 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

The EFI has 512mb of memory assigned to the integrated GPU and priority given to USB-C/Thunderbolt.

Up until the past week I was able to use 4k 3840x2160 resolution on my display in both Xorg and Wayland. As of this week, I can’t for some reason. It’s not listed in Gnome or xrandr.

I tried clearing out ~/.config/monitors.xml and forcibly adding a new mode, but that failed in both Wayland and Xorg:

[root@localhost ~]# xrandr -q
Screen 0: minimum 16 x 16, current 2560 x 1440, maximum 32767 x 32767
XWAYLAND4 connected 2560x1440+0+0 (normal left inverted right x axis y axis) 620mm x 340mm
   2560x1440     59.91*+
   1920x1440     59.90  
   1600x1200     59.87  
   1440x1080     59.87  
   1400x1050     59.86  
   1280x1024     59.89  
   1280x960      59.94  
   1152x864      59.78  
   1024x768      59.68  
   800x600       59.86  
   640x480       59.38  
   320x240       59.52  
   1920x1200     59.88  
   1680x1050     59.85  
   1440x900      59.89  
   1280x800      59.81  
   720x480       59.71  
   640x400       59.20  
   320x200       58.96  
   2048x1152     59.90  
   1920x1080     59.88  
   1600x900      59.82  
   1368x768      59.88  
   1280x720      59.86  
   1024x576      59.90  
   864x486       59.45  
   720x400       59.55  
   640x350       59.77  
[root@localhost ~]# cvt 3840 2160
# 3840x2160 59.98 Hz (CVT 8.29M9) hsync: 134.18 kHz; pclk: 712.75 MHz
Modeline "3840x2160_60.00"  712.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync
[root@localhost ~]# xrandr --newmode "3840x2160_60.00"  712.75  3840 4160 4576 5312  2160 2163 2168 2237 -hsync +vsync
[root@localhost ~]# xrandr --addmode XWAYLAND4 "3840x2160_60.00"
[root@localhost ~]# xrandr --output XWAYLAND4 --mode "3840x2160_60.00"
X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  140 (RANDR)
  Minor opcode of failed request:  21 (RRSetCrtcConfig)
  Value in failed request:  0x0
  Serial number of failed request:  22
  Current serial number in output stream:  22

dmesg shows nothing ominous:

[laurence@localhost ~]$ dmesg | grep i915
[    4.678271] i915 0000:00:02.0: enabling device (0006 -> 0007)
[    4.679223] i915 0000:00:02.0: vgaarb: deactivate vga console
[    4.681093] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=mem
[    4.681560] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4)
[    5.564005] [drm] Initialized i915 1.6.0 20200715 for 0000:00:02.0 on minor 0
[    5.693841] fbcon: i915drmfb (fb0) is primary device
[    5.693844] i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device
[   19.103114] snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
[   19.223578] mei_hdcp 0000:00:16.0-b638ab7e-94e2-4ea2-a552-d1c54b627f04: bound 0000:00:02.0 (ops i915_hdcp_component_ops [i915])

Wayland doesn’t seem to complain either:

[root@localhost log]# journalctl --since=-1day
| grep -E ‘({2}[)]’
| grep -v gdm-x-session
Jan 11 11:44:37 localhost.localdomain gnome-shell[2946]: (EE) failed to read Wayland events: Connection reset by peer
Jan 11 11:45:02 localhost.localdomain kernel: smpboot: CPU0: Intel® Core™ i5-8350U CPU @ 1.70GHz (family: 0x6, model: 0x8e, stepping: 0xa)
Jan 11 11:45:29 localhost.localdomain NetworkManager[1847]: [1610365529.6951] device (wlp3s0): driver supports Access Point (AP) mode
Jan 11 15:23:36 localhost.localdomain gnome-shell[3140]: (EE) failed to read Wayland events: Connection reset by peer
Jan 11 15:33:29 localhost.localdomain kernel: smpboot: CPU0: Intel® Core™ i5-8350U CPU @ 1.70GHz (family: 0x6, model: 0x8e, stepping: 0xa)

Jan 11 15:33:46 localhost.localdomain NetworkManager[1614]: [1610379226.9460] device (wlp3s0): driver supports Access Point (AP) mode

Packages and device firmware are all up-to-date.

Any suggestions as to how to diagnose would be much appreciated.

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Try to boot into older kernel version.

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Lenovo T480
Graphics Adapter: Intel UHD Graphics 620, NVIDIA GeForce MX150

Check your VGA ChipSet and install driver
https://www.nvidia.com/Download/driverResults.aspx/120917/en-us

Do you even have an NVIDIA card? As far as I recall, this is optional on the T480 series.

Thank you for your replies.

I have an Intel UHD adapter.

This is almost certainly due to a kernel update. I’ll try to create a patch.

2 Likes