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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
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Mehul Katara
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3 Answers3

0

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

Mehul Katara
  • 121
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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
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    Doesn't work for me (Ubuntu 13.10) – mac May 23 '14 at 07:42
  • @mac Please report it on the kernel.org bug report #57571. I have not followed the bug closely, so I do not know why it was closed as "DOCUMENTED" instead of a having a bios quirks fix. IMHO the kernel should not expose a buggy interface that, when used, results in a system hang. (Also, I do not see where this problem was actually documented...) – bain May 23 '14 at 11:01
  • I had the same problem with my Inspiron 14R 850 using Ubuntu 16.04. The boot parameter did not resolve, but creating the 20-intel.conf file worked like a charm! Upvoting! – Ramon Chiara Apr 30 '18 at 21:23
  • I tried the first method on Ubuntu 20.04 and I DO NOT recommend it. After adding the file I logged out, when I tried to log back in it just reloaded the login screen. So I rebooted the system and it gave me a blank screen. I tried several things to fix this, and if nothing worked i considered reinstalling Ubuntu from scratch. Finally I went to the terminal in recovery mode and and deleted this file. After rebooting the system everything was back to normal. – Sujit Aug 31 '20 at 14:57
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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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