Created attachment 160521 [details]
I installed Fedora21 (also tried updating the packages) but my system doesn't boot at all when in "Switchable" mode in BIOS.
The only way to have a successful boot is to use the VESA driver (nomodeset), or using the "Discrete" BIOS vga mode.
You can find the journal log attached, in contains useful call traces.
I am available to help with the debugging of this issue ;)
A few details on the machine:
Acer 5820TG, it's got an Intel HD first gen + AMD radeon HD5650.
It is a muxed switchable graphics system as far as I know
Looks like a duplicate of bug 61891. acpiphp is trying to remove the driver when the driver powers down the card because it thinks the card has been removed.
Can you try the latest patch on bug 61891?
Just for the record, I'm on Acer 4820TG with ATI Mobility Radeon HD5470 and I'm experiencing the same exact issue described in https://bugs.freedesktop.org/show_bug.cgi?id=88927
I've not tried suggested patch because I'm not practical about kernel recompiling, and I'm on Xubuntu 15.04 with kernel 3.19.0-15-generic. Anyway I reported some logs and infos on my comment there, hope it can helps: https://bugs.freedesktop.org/show_bug.cgi?id=88927#c4
Please try the latest patch on:
(In reply to Alex Deucher from comment #6)
> Please try the latest patch on:
Sorry for the delay, I just tried it and looks like it's working! Great!