0

I read many questions like mine but I didn't solve. I explain my situation: I currently have kernel 4.13.0-26-generic that solve Meltdown and Spectre on my Ubuntu 16.04 LTS.

After that upgrade I can't change brightness on my lenovo t450. The percentage is always 55% and I can't change it neither by fn and changing percentage bar on settings.

I think that downgrading kernel to 4.10.0-42-generic (my previous version) will fix it and I will wait for new version for meltdown that doesn't compromise brightness.

On my system if have: 

rc  linux-image-4.10.0-37-generic
rc  linux-image-4.10.0-38-generic                               
ii  linux-image-4.10.0-40-generic                               
ii  linux-image-4.10.0-42-generic                               
ii  linux-image-4.10.0-42-lowlatency                            
ii  linux-image-4.13.0-26-generic

How can I downgrade to 4.10.0-42? I fear about remove 4.13.0-26-generic and run sudo update-grub

linofex
  • 554
  • 9
  • 28
  • 1
    You do not have to downgrade or remove anything, although you certainly may if you wish. You select which kernel to to boot at the grub screen when you boot. – Panther Jan 17 '18 at 15:51
  • 1
    I haven't got (and like) grub screen.. – linofex Jan 17 '18 at 15:59
  • 1
    See https://askubuntu.com/questions/16042/how-to-get-to-the-grub-menu-at-boot-time – Panther Jan 17 '18 at 16:02
  • Hit escape or shift button as you boot or unhide the menu : – Panther Jan 17 '18 at 16:02
  • @Panther I don't want that screen, but I can try to load system with the previous version to see if that brightness problem is still present – linofex Jan 17 '18 at 16:04
  • 1
    @linofex yes you do. We all have. Unless you installed the ancient lilo. – Rinzwind Jan 17 '18 at 16:04
  • yes, you want to select which kernel to boot from the grub screen. You can then set the one you like as default if you wish. See https://help.ubuntu.com/community/Grub2#Saved or similar – Panther Jan 17 '18 at 16:10
  • After trying different versions of kernel I still have brightness problem, so the cause is not the kernel, but something else, so I will search other solutions.. – linofex Jan 17 '18 at 16:12
  • 1
    Identify your hardware and ask a new question – Panther Jan 17 '18 at 16:13
  • already fixed the problem creating a new /usr/share/X11/xorg.conf.d/20-intel.conf and add some options about my graphic card – linofex Jan 17 '18 at 16:18

0 Answers0