[Intel-gfx] i915 module does not find 82865G if configured as secondary

[Julien Cristau]

On Sun, Oct  9, 2011 at 19:36:27 +0100, Chris Wilson wrote:

> On Sun, 9 Oct 2011 14:44:30 +0200, Daniel Vetter <daniel at ffwll.ch> wrote:
> > On Sun, Oct 09, 2011 at 01:07:25PM +0200, Tempura San wrote:
> > > Here is the output of lspci -nn:
> > > 
> > > 00:00.0 Host bridge [0600]: Intel Corporation 82865G/PE/P DRAM
> > > Controller/Host-Hub Interface [8086:2570] (rev 02)
> > > 00:02.0 Display controller [0380]: Intel Corporation 82865G Integrated
> > > Graphics Controller [8086:2572] (rev 02)
> > 
> > The issue seems to be that the igd isn't a VGA pci class device anymore
> > when used as secondary. The below (untested) patch should allow to still
> > bind the i915 driver. Please test how far that gets us.
> 
> Note the old kernel, and probable lack of:
> 
> commit 934f992c763ae1e5eefcce8af769c16444085df7
> Author: Chris Wilson <chris at chris-wilson.co.uk>
> Date:   Thu Jan 20 13:09:12 2011 +0000
> 
>     drm/i915: Recognise non-VGA display devices
>     
>     Starting with SandyBridge (though possible with earlier hacked BIOSes),
>     the BIOS may initialise the IGFX as secondary to a discrete GPU. Prior,
>     it would simply disable the integrated GPU. So we adjust our PCI class
>     mask to match any DISPLAY_CLASS device.
>     
>     In such a configuration, the IGFX is not a primary VGA controller and
>     so should not take part in VGA arbitration, and the error return from
>     vga_client_register() is expected.
>     
>     Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>     Cc: stable at kernel.org
> 
> and
> 
> commit 5fe49d86f9d01044abf687a8cd21edef636d58aa
> Author: Chris Wilson <chris at chris-wilson.co.uk>
> Date:   Tue Feb 1 19:43:02 2011 +0000
> 
>     drm/i915: Only bind to function 0 of the PCI device
>     
>     Early chipsets (gen2/3) used function 1 as a placeholder for multi-head.
>     We used to ignore these since they were not assigned to
>     PCI_CLASS_DISPLAY_VGA. However with 934f992c7 we attempt to bind to all
>     Intel PCI_CLASS_DISPLAY devices (and functions) to work in multi-gpu
>     systems. This fails hard on gen2/3.
>     
>     Reported-by: Ferenc W??gner <wferi at niif.hu>
>     Tested-by: Ferenc W??gner <wferi at niif.hu>
>     Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=28012
>     Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>     Cc: stable at kernel.org

I'll try to get these included into a future squeeze kernel update.
Thanks.

Cheers,
Julien