Re: i915 black screen introduced by ACPI changes

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Sun, 17 Feb 2013 20:43:47 -0800
Chris Li <lkml@chrisli.org> wrote:

> My Lenovo Y580 laptop with FC18 start to get black screen after the kernel
> upgrade to 3.7.xxx
> 
> The black screen happens about the time kernel switch to using VT console.
> At the point of black screen, no response of cap locks key led no network
> connection. The machine seems dead.

Can you set up netconsole and see if you can get any output from the
boot, if we're lucky maybe you'll see a panic...

> The CPU is i7 and it has two video card. The Intel build-in video card
> and Gtx 660M Nvidia card.
> 
> This is very annoying. I did some poking around it:
> - It was fine on the FC18 3.6.xxx kernel before the upgrade.
> - The black screen exists with FC18 3.7.xxx kernel
> - The black screen also exists in latest tip of linux-2.6.
> - Switch to multi-user mode booting does not get rid of the black screen.
> - Get rid of the "rhrb quit" does not help either.
> - When the black screen happen, cap lock LED does not response to cap locks.
> - No networking when black screen happen. The only thing to do is
> reboot the system.
> - Adding "i915.modeset=0" will allow the kernel to boot into GUI login. However,
>   logout of X will cause the machine to hang similar to the black screen.
> - Suspend and resume will get stuck at the black screen with"i915.modeset=0".
> - Kernel console and X is using the Intel driver for display.

I don't know about the ACPI change mentioned, but ACPI is involved in
dual-GPU configurations.  Maybe the change affected the default
behavior and pointed more functions at the nVidia device rather than
the Intel?

-- 
Jesse Barnes, Intel Open Source Technology Center