Booting kernel 3.9 I get an intense brightness/alpha in the (external) LCD. The problem appears the moment the kernel begins to boot in the (fb) text console and carries over to X as well. Due to config option deps I can't replace the fb console with the classic VGA one. I suppose I could find a way to turn down the brightness in X by a software means, but this is a bug that shouldn't be there. There is no change in Xorg.0.log when X runs under 3.8 and 3.9. I have an embedded Sandy Bridge Intel GPU. The LCD is connected to a laptop via HDMI. I can't tell for sure if the brightness has risen in the laptop built-in LCD too - I rarely use it these days - but my guess is that it has risen there too. Reproducible: Always
Created attachment 348786 [details] emerge --info
Created attachment 348788 [details] .config The problem persists even if I remove x2apic support and (almost) everything under ACPI / power mgmt. These are the changes between 3.8.12 and 3.9.3 in the Drivers -> Graphics area: CONFIG_DRM_TTM=m CONFIG_DRM_GMA500=m CONFIG_HDMI=y Neither of these was present in 3.8. I don't load these modules anyway, though, and CONFIG_HDMI cannot be (un)set manually and is auto-selected by CONFIG_DRM.
This issue doesn't go away with disabling MAXSMP (bug 470792).
@Roman, thanks for the report. Would be better if the report goes directly to the upstream bugzilla.
Agreed, please file this at https://bugzilla.kernel.org/ and provide us the link to the upstream bug; thanks in advance.
Daniel Vetter (upstream) replied: " This is intended behaviour, we've implemented the automatic selection of broadcast rbg support for hdmi according to spec. I know specs are crap and even more so wrt hdmi screens, but this is about as good as it'll get. If you're unhappy with the new mode you can override it with the "RBG Broadcast" xrandr connector property attached to the HDMI output. "
