1. COMPANY
  2. PRODUCTS
  3. SERVICES
  4. NEWS
  5. CONTACT
  6. SHOP

How to fix backlight issue on IdeaPad y510p

Today I decide to switch to latest kernel (3.17-rc1) on my IdeaPad y510p. I hit only one annoying problem until now - after booting my main screen was dimmed. I tried all instructions from top google hits for all possible configurations of keywords linux, y510p, backlight issue, etc.

Especially I tried all methods from Arch Wiki.

Finally I found solution, by greping modinfo for my Intel graphics card:

1
2
3
4
5
[23:55:24] pietrushnic:~ $ sudo modinfo i915|grep backlight
parm:           invert_brightness:Invert backlight brightness (-1 force normal, \
 0 machine defaults, 1 force inversion), please report PCI device ID, subsystem \
vendor and subsystem device ID to dri-devel@lists.freedesktop.org, if your \
machine needs it. It will then be included in an upcoming module version. (int)

So simple modification in /etc/default/grub by adding kernel parameter to GRUB_CMDLINE_LINUX_DEFAULT fix the issue:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="rcutree.rcu_idle_gp_delay=1 i915.invert_brightness=1"
GRUB_CMDLINE_LINUX=""
(...)

After that:

1
sudo update-grub

And all things should work fine.


Piotr Król
Founder and Embedded Systems Consultant at 3mdeb as well as CTO of vitroTV. Passionate about building firmware that enables advanced hardware features in modern products. Dedicated to customers that treat embedded software security and upgradability as forethought. In favor of fixed price projects with the clear definition of success. Available as freelance CTO for startups and small business.