Comment 98 for bug 1007765

On Fri, Aug 23, 2013 at 09:05:34AM -0000, Aditya wrote:
> Thanks Marwan for the detailed description of the bug.

You're welcome.

> I just posted this as a fix for the users who were unable to change brightness, and I had no idea how deep the roots of this bug are.

And, I don't blame you. I just took it as an oppurtunity for explaining the
root cause of the problem in order to reduce the amount of trial-and-error for
poeple experiencing the same problem.

> In my case, both acpi_video0 and acpi_video1 do not work, i.e. the brightness does not change and the system is functional.
> When I use acpi_backlight=vendor things are different even if I disable nmi_watchdog .

But this thread is about the problem of the freeze that happens on some systems
when adjusting the brightness, not about the issue of the brightness controls
not working, while the system is functional. Disabling nmi_watchdog just makes
us avoid this freeze. You are talking about a different issue here. Maybe you
need to open a new bug report for this problem.