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Barton Chittenden
Asked: 2016-07-01 20:17:30 +0800 CST

Laptop resolution lowered after automatic updates

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I'm running Xubuntu 14.04 on a laptop with 1920x1024 native resolution. After the latest automatic update (including kernel upgrade to 3.13.0-92-generic), the maximum available screen resolution dropped to 1024x768.

$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1024 x 768, current 1024 x 768, maximum 1024 x 768
default connected 1024x768+0+0 0mm x 0mm
   1024x768       76.0*

I'm using nvidia-352 driver; lspci shows

01:00.0 VGA compatible controller: NVIDIA Corporation GK107M [GeForce GTX 660M] (rev a1)

Following https://wiki.ubuntu.com/X/Troubleshooting/Resolution#Problem:__Wrong_resolutions.2C_refresh_rates.2C_or_monitor_specs , I looked at /var/log/Xorg.0.log, which shows:

[    49.227] (EE) NVIDIA: Failed to initialize the NVIDIA kernel module. Please see the
[    49.227] (EE) NVIDIA:     system's kernel log for additional error messages and
[    49.227] (EE) NVIDIA:     consult the NVIDIA README for details.
[    49.227] (EE) [drm] KMS not enabled
[    49.227] (EE) open /dev/dri/card0: No such file or directory
[    49.227] (WW) Falling back to old probe method for modesetting
[    49.227] (EE) open /dev/dri/card0: No such file or directory

The kernel log is 0 bytes. Not sure what that's about.

sudo get-edid|parse-edid crashed, but before it did, it gave me

This is read-edid version 3.0.1. Prepare for some fun.
Attempting to use i2c interface
Looks like no busses have an EDID. Sorry!
Attempting to use the classical VBE interface

    Performing real mode VBE call
    Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
Partial Read... Try again

[edit] according to @mikewhatever, Kernel 3.13.0-92-generic is still in the proposed repository. Indeed:

$ apt-cache policy linux-image-3.13.0-92-generic
linux-image-3.13.0-92-generic:
  Installed: 3.13.0-92.139
  Candidate: 3.13.0-92.139
  Version table:
  *** 3.13.0-92.139 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty-proposed/main amd64 Packages
        100 /var/lib/dpkg/status

linux-image-3.13.0-91-generic isn't installed. Rebooting into 3.13.0-89-generic did not fix the issue.

EDIT:

The Kernel upgrade turned out not to be the issue -- the problem was an upgrade to secure-boot, which disabled the drivers.

nvidia

2 Answers

  1. Best Answer

    It turns out that the Kernel upgrade was a red herring -- the issue was the secure boot upgrade that happened at the same time, which blacklisted the NVidia drivers.

    This is essentially the same issue as found here: Ubuntu 16.04 kernel 4.4.0-21 not loading nvidia/vboxdrv modules anymore (Required key not available)

    Confirmed by running

    $ sudo modprobe -v nvidia
insmod /lib/modules/3.13.0-92-generic/updates/dkms/nvidia_361.ko 
modprobe: ERROR: could not insert 'nvidia_361': Required key not available

    Fixed by disabling secure boot in BIOS

    • 2

  2. Same problem, here. I booted into 3.13.0-91-generic and everything is fine. However, booting into 3.13.0-92-generic introduces the problem. It appears as if my Nvidia X Server settings have been completely wiped in 3.13.0-92-generic.

    Edit: Disable secure boot as mentioned in the accepted answer.

    • 0