Comment 38 for bug 35223

@jango - thanks for helping and putting this with 100 paper cuts.

You are right that there has been a little mix up during reporting, but this is a real bug and this is the correct place to discuss the bug where:
resetting your laptop resets brightness to 100% regardless of your settings.

This bug occurs across many laptops, so I don't think it is necessary to file a new report with information on each laptop.

In fact, this bug has been traced to the ACPI where the ACPI object for brightness is an optional function not implemented by every laptop's ACPI. If your laptop does not have this optional function, you will see this bug. This allows us the work around listed above and a starting point to fix this bug.