Comment 158 for bug 1098216

I'm already trying to get this information to Lenovo. However at this point it's in the wild and there will always be broken machines, so it would be nice if we had a way to deal with it. Quirking that many machines might not be well received, though any other solution I can think of seems even worse. Unless all the broken machines have some other attribute in common, like the firmware version, that we can use for quirking instead. That would be good.

Fwiw, I suspect the reason it works under Windows is that it must be trying to do a smooth backlight adjustment by writing every brightness value between current_brightness and new_brightness, so you at least end up with the last valid brightness value written.