[PATCH 1/2 v2] vgaarb: Don't default exclusively to first video device with mem+io

[Bjorn Helgaas]

On Fri, Sep 12, 2014 at 5:19 AM, Bruno Prémont
<bonbons at linux-vserver.org> wrote:
> Bjorn,
>
> What is missing to get these two patches pushed to Linus?

Sorry, I've been working on some other regressions and overlooked this
one.  If you open a bugzilla report and mark it as a regression, that
will help keep this on my radar.

Bjorn

> On Thu, 28 Aug 2014 22:47:50 +0200 Bruno Prémont wrote:
>> On Tue, 26 August 2014 Andreas Noever <andreas.noever at gmail.com> wrote:
>> > On Sun, Aug 24, 2014 at 11:09 PM, Bruno Prémont wrote:
>> > > With commit 20cde694027e boot video device detection was moved from
>> > > efifb to x86 and ia64 pci/fixup.c.
>> > >
>> > > For dual-GPU Apple computers above change represents a regression as
>> > > code in efifb did forcefully override vga_default_device while the
>> > > merge did not (vgaarb happens prior to PCI fixup).
>> > >
>> > > To improve on initial device selection by vgaarb (it cannot know if
>> > > PCI device not behind bridges see/decode legacy VGA I/O or not), move
>> > > the screen_info based check from pci_video_fixup to vgaarb's init
>> > > function and use it to refine/override decision taken while adding
>> > > the individual PCI VGA devices.
>> > > This way PCI fixup has no reason to adjust vga_default_device
>> > > anymore but can depend on its value for flagging shadowed VBIOS.
>> > >
>> > > This has the nice benefit of removing duplicated code but does
>> > > introduce a #if defined() block in vgaarb.
>> > > Not all architectures have screen_info and would cause compile to
>> > > fail without it.
>> > >
>> > > Reported-By: Andreas Noever <andreas.noever at gmail.com>
>> > > CC: Matthew Garrett <matthew.garrett at nebula.com>
>> > > CC: stable at vger.kernel.org # v3.5+
>> > > Signed-off-by: Bruno Prémont <bonbons at linux-vserver.org>
>> > > ---
>> > > Andreas, does this work properly for you, including the improvement
>> > > on i915 complaint about VBIOS going from KERN_ERR to KERN_INFO?
>> > Yep, thanks!
>> >
>> > >
>> > > Other arches using PCI and vgaarb that have screen_info may want
>> > > to be added to the #if defined() block or even introduce a new
>> > > CONFIG_HAVE_SCREEN_INFO or similar...
>>
>> Bjorn, can you queue these two patches, probably going through -next
>> for a week and passing them to Linus for -rc4, adding Andreas's Tested-by
>> to Patch 1/2 v2?
>>
>> Thanks,
>> Bruno