Comment 97 for bug 1007765

Thanks Marwan for the detailed description of the bug.
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.

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 .

Are there any tests that I run?