diff mbox

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

Message ID 20140824230953.7c04890f@neptune.home (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Bruno Prémont Aug. 24, 2014, 9:09 p.m. UTC
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@gmail.com>
CC: Matthew Garrett <matthew.garrett@nebula.com>
CC: stable@vger.kernel.org # v3.5+
Signed-off-by: Bruno Prémont <bonbons@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?


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...


 arch/ia64/pci/fixup.c    | 24 +-----------------------
 arch/x86/pci/fixup.c     | 24 +-----------------------
 drivers/gpu/vga/vgaarb.c | 38 +++++++++++++++++++++++++++++++++++++-
 3 files changed, 39 insertions(+), 47 deletions(-)

Comments

Andreas Noever Aug. 26, 2014, 3:32 p.m. UTC | #1
On Sun, Aug 24, 2014 at 11:09 PM, Bruno Prémont
<bonbons@linux-vserver.org> 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@gmail.com>
> CC: Matthew Garrett <matthew.garrett@nebula.com>
> CC: stable@vger.kernel.org # v3.5+
> Signed-off-by: Bruno Prémont <bonbons@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...
>
>
>  arch/ia64/pci/fixup.c    | 24 +-----------------------
>  arch/x86/pci/fixup.c     | 24 +-----------------------
>  drivers/gpu/vga/vgaarb.c | 38 +++++++++++++++++++++++++++++++++++++-
>  3 files changed, 39 insertions(+), 47 deletions(-)
>
> diff --git a/arch/ia64/pci/fixup.c b/arch/ia64/pci/fixup.c
> index ec73b2c..fc505d5 100644
> --- a/arch/ia64/pci/fixup.c
> +++ b/arch/ia64/pci/fixup.c
> @@ -38,27 +38,6 @@ static void pci_fixup_video(struct pci_dev *pdev)
>                 return;
>         /* Maybe, this machine supports legacy memory map. */
>
> -       if (!vga_default_device()) {
> -               resource_size_t start, end;
> -               int i;
> -
> -               /* Does firmware framebuffer belong to us? */
> -               for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> -                       if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM))
> -                               continue;
> -
> -                       start = pci_resource_start(pdev, i);
> -                       end  = pci_resource_end(pdev, i);
> -
> -                       if (!start || !end)
> -                               continue;
> -
> -                       if (screen_info.lfb_base >= start &&
> -                           (screen_info.lfb_base + screen_info.lfb_size) < end)
> -                               vga_set_default_device(pdev);
> -               }
> -       }
> -
>         /* Is VGA routed to us? */
>         bus = pdev->bus;
>         while (bus) {
> @@ -83,8 +62,7 @@ static void pci_fixup_video(struct pci_dev *pdev)
>                 pci_read_config_word(pdev, PCI_COMMAND, &config);
>                 if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
>                         pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
> -                       dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
> -                       vga_set_default_device(pdev);
> +                       dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n");
>                 }
>         }
>  }
> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
> index c61ea57..9a2b710 100644
> --- a/arch/x86/pci/fixup.c
> +++ b/arch/x86/pci/fixup.c
> @@ -326,27 +326,6 @@ static void pci_fixup_video(struct pci_dev *pdev)
>         struct pci_bus *bus;
>         u16 config;
>
> -       if (!vga_default_device()) {
> -               resource_size_t start, end;
> -               int i;
> -
> -               /* Does firmware framebuffer belong to us? */
> -               for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> -                       if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM))
> -                               continue;
> -
> -                       start = pci_resource_start(pdev, i);
> -                       end  = pci_resource_end(pdev, i);
> -
> -                       if (!start || !end)
> -                               continue;
> -
> -                       if (screen_info.lfb_base >= start &&
> -                           (screen_info.lfb_base + screen_info.lfb_size) < end)
> -                               vga_set_default_device(pdev);
> -               }
> -       }
> -
>         /* Is VGA routed to us? */
>         bus = pdev->bus;
>         while (bus) {
> @@ -371,8 +350,7 @@ static void pci_fixup_video(struct pci_dev *pdev)
>                 pci_read_config_word(pdev, PCI_COMMAND, &config);
>                 if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
>                         pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
> -                       dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
> -                       vga_set_default_device(pdev);
> +                       dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n");
>                 }
>         }
>  }
> diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
> index d2077f0..cffdff9 100644
> --- a/drivers/gpu/vga/vgaarb.c
> +++ b/drivers/gpu/vga/vgaarb.c
> @@ -41,6 +41,7 @@
>  #include <linux/poll.h>
>  #include <linux/miscdevice.h>
>  #include <linux/slab.h>
> +#include <linux/screen_info.h>
>
>  #include <linux/uaccess.h>
>
> @@ -585,8 +586,11 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
>          */
>  #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
>         if (vga_default == NULL &&
> -           ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK))
> +           ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) {
> +               pr_info("vgaarb: setting as boot device: PCI:%s\n",
> +                       pci_name(pdev));
>                 vga_set_default_device(pdev);
> +       }
>  #endif
>
>         vga_arbiter_check_bridge_sharing(vgadev);
> @@ -1320,6 +1324,38 @@ static int __init vga_arb_device_init(void)
>         pr_info("vgaarb: loaded\n");
>
>         list_for_each_entry(vgadev, &vga_list, list) {
> +#if defined(CONFIG_X86) || defined(CONFIG_IA64)
> +               /* Override I/O based detection done by vga_arbiter_add_pci_device()
> +                * as it may take the wrong device (e.g. on Apple system under EFI).
> +                *
> +                * Select the device owning the boot framebuffer if there is one.
> +                */
> +               resource_size_t start, end;
> +               int i;
> +
> +               /* Does firmware framebuffer belong to us? */
> +               for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> +                       if (!(pci_resource_flags(vgadev->pdev, i) & IORESOURCE_MEM))
> +                               continue;
> +
> +                       start = pci_resource_start(vgadev->pdev, i);
> +                       end  = pci_resource_end(vgadev->pdev, i);
> +
> +                       if (!start || !end)
> +                               continue;
> +
> +                       if (screen_info.lfb_base < start ||
> +                           (screen_info.lfb_base + screen_info.lfb_size) >= end)
> +                               continue;
> +                       if (!vga_default_device())
> +                               pr_info("vgaarb: setting as boot device: PCI:%s\n",
> +                                       pci_name(vgadev->pdev));
> +                       else if (vgadev->pdev != vga_default_device())
> +                               pr_info("vgaarb: overriding boot device: PCI:%s\n",
> +                                       pci_name(vgadev->pdev));
> +                       vga_set_default_device(vgadev->pdev);
> +               }
> +#endif
>                 if (vgadev->bridge_has_one_vga)
>                         pr_info("vgaarb: bridge control possible %s\n", pci_name(vgadev->pdev));
>                 else
> --
> 1.8.5.5
>
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Bruno Prémont Aug. 28, 2014, 8:47 p.m. UTC | #2
On Tue, 26 August 2014 Andreas Noever <andreas.noever@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@gmail.com>
> > CC: Matthew Garrett <matthew.garrett@nebula.com>
> > CC: stable@vger.kernel.org # v3.5+
> > Signed-off-by: Bruno Prémont <bonbons@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
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Bruno Prémont Sept. 12, 2014, 11:19 a.m. UTC | #3
Bjorn,

What is missing to get these two patches pushed to Linus?

Bruno


On Thu, 28 Aug 2014 22:47:50 +0200 Bruno Prémont wrote:
> On Tue, 26 August 2014 Andreas Noever <andreas.noever@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@gmail.com>
> > > CC: Matthew Garrett <matthew.garrett@nebula.com>
> > > CC: stable@vger.kernel.org # v3.5+
> > > Signed-off-by: Bruno Prémont <bonbons@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
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Bjorn Helgaas Sept. 12, 2014, 2:28 p.m. UTC | #4
On Fri, Sep 12, 2014 at 5:19 AM, Bruno Prémont
<bonbons@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@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@gmail.com>
>> > > CC: Matthew Garrett <matthew.garrett@nebula.com>
>> > > CC: stable@vger.kernel.org # v3.5+
>> > > Signed-off-by: Bruno Prémont <bonbons@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
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Dave Airlie Sept. 18, 2014, 11:26 p.m. UTC | #5
On 13 September 2014 00:28, Bjorn Helgaas <bhelgaas@google.com> wrote:
> On Fri, Sep 12, 2014 at 5:19 AM, Bruno Prémont
> <bonbons@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.

My MBP is crying? can we get these merged, I can handle if if you want
to ack them for me!

Dave.
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Bjorn Helgaas Sept. 19, 2014, 5:18 a.m. UTC | #6
On Fri, Sep 19, 2014 at 09:26:58AM +1000, Dave Airlie wrote:
> On 13 September 2014 00:28, Bjorn Helgaas <bhelgaas@google.com> wrote:
> > On Fri, Sep 12, 2014 at 5:19 AM, Bruno Prémont
> > <bonbons@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.
> 
> My MBP is crying? can we get these merged, I can handle if if you want
> to ack them for me!

Yep, it's in linux-next and I'll send Linus a pull request for the tag [1]
tomorrow.  I meant to send it tonight, but I had to fix my for-linus branch
to remove a duplicate commit and I don't want to send the pull request
immediately afterwards.

Bjorn

[1] https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/tag/?h=for-linus&id=pci-v3.17-fixes-2
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diff mbox

Patch

diff --git a/arch/ia64/pci/fixup.c b/arch/ia64/pci/fixup.c
index ec73b2c..fc505d5 100644
--- a/arch/ia64/pci/fixup.c
+++ b/arch/ia64/pci/fixup.c
@@ -38,27 +38,6 @@  static void pci_fixup_video(struct pci_dev *pdev)
 		return;
 	/* Maybe, this machine supports legacy memory map. */
 
-	if (!vga_default_device()) {
-		resource_size_t start, end;
-		int i;
-
-		/* Does firmware framebuffer belong to us? */
-		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
-			if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM))
-				continue;
-
-			start = pci_resource_start(pdev, i);
-			end  = pci_resource_end(pdev, i);
-
-			if (!start || !end)
-				continue;
-
-			if (screen_info.lfb_base >= start &&
-			    (screen_info.lfb_base + screen_info.lfb_size) < end)
-				vga_set_default_device(pdev);
-		}
-	}
-
 	/* Is VGA routed to us? */
 	bus = pdev->bus;
 	while (bus) {
@@ -83,8 +62,7 @@  static void pci_fixup_video(struct pci_dev *pdev)
 		pci_read_config_word(pdev, PCI_COMMAND, &config);
 		if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
 			pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
-			dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
-			vga_set_default_device(pdev);
+			dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n");
 		}
 	}
 }
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index c61ea57..9a2b710 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -326,27 +326,6 @@  static void pci_fixup_video(struct pci_dev *pdev)
 	struct pci_bus *bus;
 	u16 config;
 
-	if (!vga_default_device()) {
-		resource_size_t start, end;
-		int i;
-
-		/* Does firmware framebuffer belong to us? */
-		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
-			if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM))
-				continue;
-
-			start = pci_resource_start(pdev, i);
-			end  = pci_resource_end(pdev, i);
-
-			if (!start || !end)
-				continue;
-
-			if (screen_info.lfb_base >= start &&
-			    (screen_info.lfb_base + screen_info.lfb_size) < end)
-				vga_set_default_device(pdev);
-		}
-	}
-
 	/* Is VGA routed to us? */
 	bus = pdev->bus;
 	while (bus) {
@@ -371,8 +350,7 @@  static void pci_fixup_video(struct pci_dev *pdev)
 		pci_read_config_word(pdev, PCI_COMMAND, &config);
 		if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
 			pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
-			dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
-			vga_set_default_device(pdev);
+			dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n");
 		}
 	}
 }
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index d2077f0..cffdff9 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -41,6 +41,7 @@ 
 #include <linux/poll.h>
 #include <linux/miscdevice.h>
 #include <linux/slab.h>
+#include <linux/screen_info.h>
 
 #include <linux/uaccess.h>
 
@@ -585,8 +586,11 @@  static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
 	 */
 #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
 	if (vga_default == NULL &&
-	    ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK))
+	    ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) {
+		pr_info("vgaarb: setting as boot device: PCI:%s\n",
+			pci_name(pdev));
 		vga_set_default_device(pdev);
+	}
 #endif
 
 	vga_arbiter_check_bridge_sharing(vgadev);
@@ -1320,6 +1324,38 @@  static int __init vga_arb_device_init(void)
 	pr_info("vgaarb: loaded\n");
 
 	list_for_each_entry(vgadev, &vga_list, list) {
+#if defined(CONFIG_X86) || defined(CONFIG_IA64)
+		/* Override I/O based detection done by vga_arbiter_add_pci_device()
+		 * as it may take the wrong device (e.g. on Apple system under EFI).
+		 *
+		 * Select the device owning the boot framebuffer if there is one.
+		 */
+		resource_size_t start, end;
+		int i;
+
+		/* Does firmware framebuffer belong to us? */
+		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+			if (!(pci_resource_flags(vgadev->pdev, i) & IORESOURCE_MEM))
+				continue;
+
+			start = pci_resource_start(vgadev->pdev, i);
+			end  = pci_resource_end(vgadev->pdev, i);
+
+			if (!start || !end)
+				continue;
+
+			if (screen_info.lfb_base < start ||
+			    (screen_info.lfb_base + screen_info.lfb_size) >= end)
+				continue;
+			if (!vga_default_device())
+				pr_info("vgaarb: setting as boot device: PCI:%s\n",
+					pci_name(vgadev->pdev));
+			else if (vgadev->pdev != vga_default_device())
+				pr_info("vgaarb: overriding boot device: PCI:%s\n",
+					pci_name(vgadev->pdev));
+			vga_set_default_device(vgadev->pdev);
+		}
+#endif
 		if (vgadev->bridge_has_one_vga)
 			pr_info("vgaarb: bridge control possible %s\n", pci_name(vgadev->pdev));
 		else