I just realised that after my recent update to 3.16.1-1-ARCH my laptop boots with a max brightness setting. When i try to dim it to the lowest minimum, the screen goes black and nothing less than a reboot or attempted sleep brings it back. The keys works fine when lowering or maximizing but once the black screen sets in, they don't respond anymore. Any help will be sincerely appreciated.
My laptop is a Sony Vaio S red edition, Intel Core i5-3210M, Intel HD Graphics 4000
I guess you'll probably have more chance to get it fixed by filing a bug report here under ACPI https://bugzilla.kernel.org/ as this looks like a kernel bug.
I guess so... The intel HD 4000 series seems to be attracting a lot of bugs with each update.