2

I have dell n5010

my system hang when I try to change brightness of the display and this happen only when my system on battery

please help how to solve this problem

bain
  • 12,200
Mehul Katara
  • 121

3 Answers3

0

After the update of Ubuntu 16.04, the problem of brightness solved.

Mehul Katara
  • 121
0

The Dell Inspiron N5010 (and other Dell laptops eg. Dell Studio 1558, Inspiron 1464, Inspiron 1564, Inspiron M5010) has a bug in the firmware that causes it to hang in the backlight code under certain scenarios. This is kernel.org bug #57571 - Dell Inspiron N5010: freeze on adjusting brightness unless acpi_backlight=vendor is specified on boot and Launchpad bug #1007765 - brightness adjusting crashes system. There are two workarounds that may help:

  • Create the file /usr/share/X11/xorg.conf.d/20-intel.conf with contents:

    Section "Device"
    Identifier  "card0"
    Driver      "intel"
    Option      "Backlight"    "intel_backlight"
    BusID       "PCI:0:2:0"
EndSection

    Log out and log back in again then test.

  • Add acpi_backlight=vendor to the boot parameters (some users report that this does not work for them)

bain
  • 12,200
0

For people that stumbled upon this years later (like me). Neither of these approaches worked for me. Probably because I have an AMD/ATI graphics card which is using the radeon_bl0 interface.

What fixed it for me was adding

echo 0 >/proc/sys/kernel/nmi_watchdog

to 

/etc/rc.local

A longer explanation to this workaround can be found here Comment 96 for bug 1007765

C. J
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