Re: Bug#706603: general: laptop freeze on adjusting brightness

[Marwan Tanager <marwan.tngr@gmail.com>]

On Thu, May 02, 2013 at 05:23:42AM -0400, giri wrote:
> Package: general
> Severity: normal
> 
> Dear Maintainer,
> *** Please consider answering these questions, where appropriate ***
> 
>    * What led up to the situation?
>      while adjusting screen brightness
> 
>    * What exactly did you do (or not do) that was effective (or
>      ineffective)?
>      used laptop dedicated buttons to adjust screen brightness
> 
>    * What was the outcome of this action?
>      system freeze
> 
>    * What outcome did you expect instead?
>      screen brightness to be adjusted without problems

I had the same problem a while ago on a Dell Inspiron N5010, and I was able to 
work around it by using the following configuration in /etc/default/grub

	GRUB_CMDLINE_LINUX="acpi_backlight=vendor"

There is actually an open kernel bug report regarding this issue in 
bugzilla.kernel.org:

	[1] https://bugzilla.kernel.org/show_bug.cgi?id=15895

Based on the discussions on that thread, you may also want to try the following 
kernel boot parameter, if the one above is not effective:

	pcie_aspm=force

For me, the second one was irrelevant, and the issue has gone by only including 
acpi_backlight=vendor. Note, however, that this workarounds are not reliable 
across all systems with intel graphics. They might fix the issue on some 
systems, but are completely useless on others, so I hope this helps in your 
case.


--
	Marwan