Re: Kernel Freeze with American Megatrends BIOS

From: Emil Velikov
Date: Tue Aug 30 2016 - 11:49:09 EST

On 30 August 2016 at 16:25, Roland Singer <roland.singer@xxxxxxxxxxxxx> wrote:
> I tried these scenarios:
> 1. Booted the system without the bbswitch module. The nouveau module
> was loaded and is responsible for the power management of the GPU.
> The graphical session freezes after some minutes...
> 2. Booted the system without bbswitch and with nouveau blacklisted.
> Manually loaded bbswitch to switch off the discrete GPU.
> Same freeze after a while or by explicitly obtaining the GPU state.
> Is there a possibility to switch off the discrete card without bbswitch?
> If this is possible, then I could test this without nouveau and bbswitch
> at all. If the system hangs, then it is not the video driver nor bbswitch.
As Ilia mentioned acpi_call should do it. You can also check with the
nouveau/bbwswitch code to see which ones they use in your case and
bash it manually. It might be that the 'wrong one' gets used thus
things going horribly wrong.