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  1. Bug #1007765
  2. Comment #100

Comment 100 for bug 1007765

Revision history for this message
Marwan Tanager (marwan-tngr) wrote : Re: [Bug 1007765] Re: brightness adjusting crashes system

On Fri, Aug 23, 2013 at 04:09:46PM -0000, Aditya wrote:
> Hi,
> by different I mean that the system freezes in both the situations, with nmi_watchdog enabled and disabled, and this happens as soon as I soon as I change the brightness levels, and this is the reason I actually reached this bug report.

Then, let's do some testing.

Could you please do the following:

 - Boot the system with acpi_backlight=vendor

 - sudo echo 0 >/proc/sys/kernel/nmi_watchdog

 - cat /proc/sys/kernel/nmi_watchdog (make sure the output is 0)

 - Try changing the brightness using the keyboard keys, and see whether
   a freeze would happens or not.

Note that if you just put echo 0 >/proc/sys/kernel/nmi_watchdog in
/etc/rc.local, then you are going to need to reboot the system in order for the
script to be executed.

If a freeze still happens, then my guess is that there is another source of
NMIs on your system other than nmi_watchdog that still conflicts with the
vendor firmware backlight driver.