Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[kernel test robot]

:::::: 
:::::: Manual check reason: "linux-review patch is more than 7 days old, verify it wasn't already superseded"
:::::: 

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20261028094634.766723-1-wuqianhai@loongson.cn>
References: <20261028094634.766723-1-wuqianhai@loongson.cn>
TO: wuqianhai@loongson.cn
TO: bhelgaas@google.com
CC: wuqianhai <wuqianhai@loongson.cn>
CC: linux-pci@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: tzimmermann@suse.de
CC: javierm@redhat.com
CC: dri-devel@lists.freedesktop.org

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus linus/master v7.4-rc2 next-20261109]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/wuqianhai-loongson-cn/PCI-VGA-Fix-boot-device-detection-after-framebuffer-relocation/20261028-174634
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20261028094634.766723-1-wuqianhai%40loongson.cn
patch subject: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation
:::::: branch date: 7 hours ago
:::::: commit date: 7 hours ago
config: alpha-defconfig (https://download.01.org/0day-ci/archive/20261111/202611110347.EpCc8ug6-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 16.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261111/202611110347.EpCc8ug6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202611110347.EpCc8ug6-lkp@intel.com/

All errors (new ones prefixed by >>):

   alpha-linux-ld: drivers/pci/vgaarb.o: in function `vga_arb_device_init':
   drivers/pci/vgaarb.c:1536:(.init.text+0x8): undefined reference to `screen_info_apply_fixups'
>> alpha-linux-ld: drivers/pci/vgaarb.c:1536:(.init.text+0x24): undefined reference to `screen_info_apply_fixups'

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[kernel test robot]

:::::: 
:::::: Manual check reason: "linux-review patch is more than 7 days old, verify it wasn't already superseded"
:::::: 

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <20261028094634.766723-1-wuqianhai@loongson.cn>
References: <20261028094634.766723-1-wuqianhai@loongson.cn>
TO: wuqianhai@loongson.cn
TO: bhelgaas@google.com
CC: wuqianhai <wuqianhai@loongson.cn>
CC: linux-pci@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: tzimmermann@suse.de
CC: javierm@redhat.com
CC: dri-devel@lists.freedesktop.org

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus linus/master v7.4-rc2 next-20261110]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/wuqianhai-loongson-cn/PCI-VGA-Fix-boot-device-detection-after-framebuffer-relocation/20261028-174634
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20261028094634.766723-1-wuqianhai%40loongson.cn
patch subject: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation
:::::: branch date: 27 hours ago
:::::: commit date: 27 hours ago
config: xtensa-common_defconfig (https://download.01.org/0day-ci/archive/20261111/202611112305.j7RhAOKu-lkp@intel.com/config)
compiler: xtensa-linux-gcc (GCC) 16.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261111/202611112305.j7RhAOKu-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202611112305.j7RhAOKu-lkp@intel.com/

All errors (new ones prefixed by >>):

>> xtensa-linux-ld: drivers/pci/vgaarb.o:(.init.literal+0x14): undefined reference to `screen_info_apply_fixups'
   xtensa-linux-ld: drivers/pci/vgaarb.o: in function `vga_arb_device_init':
   vgaarb.c:(.init.text+0x3): undefined reference to `screen_info_apply_fixups'

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[wuqianhai]

From: wuqianhai <wuqianhai@loongson.cn>

PCI resource assignment can relocate the firmware framebuffer BAR, which
leaves the base address in screen_info stale.  The VGA arbiter then calls
screen_info_pci_dev() from vga_is_firmware_default(), which fails to match
the framebuffer against any PCI device's BARs.  As a result, the boot VGA
device is not recognized and the arbiter may select the wrong default
device.

Fix this by calling screen_info_apply_fixups() in vga_arb_device_init()
before adding the VGA devices.  This relocates lfb_base to the assigned
BAR address so that vga_is_firmware_default() matches the boot device
again.

Tested on a LoongArch platform, with vga_is_firmware_default()
additionally enabled for CONFIG_LOONGARCH via local changes.

Fixes: 337bf13aa9ddab8ae47f2677ab75cf69ae33437b ("PCI/VGA: Replace vga_is_firmware_default() with a screen info check")
Signed-off-by: wuqianhai <wuqianhai@loongson.cn>
---
 drivers/pci/vgaarb.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index 3e58b2c05c85..aca594651f58 100644
--- a/drivers/pci/vgaarb.c
+++ b/drivers/pci/vgaarb.c
@@ -1527,6 +1527,14 @@ static int __init vga_arb_device_init(void)
 	int rc;
 	struct pci_dev *pdev;
 
+	/*
+	 * PCI resource assignment may have relocated the firmware
+	 * framebuffer BAR. Update screen_info's lfb_base so that
+	 * vga_is_firmware_default() can match it against the boot
+	 * device's relocated resource.
+	 */
+	screen_info_apply_fixups();
+
 	rc = misc_register(&vga_arb_device);
 	if (rc < 0)
 		pr_err("error %d registering device\n", rc);
-- 
2.34.1

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] PCI/VGA: premature and duplicate screen_info_apply_fixups() in vga_arb_device_init()
- [Medium] PCI/VGA: undefined reference to screen_info_apply_fixups() when !SCREEN_INFO
--

commit da40d2d05299ef123ed4789d2ecb58829165fbe3
Author: wuqianhai <wuqianhai@loongson.cn>

PCI/VGA: Fix boot device detection after framebuffer relocation

This commit calls screen_info_apply_fixups() in vga_arb_device_init() so that
screen_info's lfb_base is updated before VGA devices are registered and
checked by vga_is_firmware_default().

> diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
> index 3e58b2c05c854..aca594651f580 100644
> --- a/drivers/pci/vgaarb.c
> +++ b/drivers/pci/vgaarb.c
> @@ -1527,6 +1527,14 @@ static int __init vga_arb_device_init(void)
>  	int rc;
>  	struct pci_dev *pdev;
>  
> +	/*
> +	 * PCI resource assignment may have relocated the firmware
> +	 * framebuffer BAR. Update screen_info's lfb_base so that
> +	 * vga_is_firmware_default() can match it against the boot
> +	 * device's relocated resource.
> +	 */
> +	screen_info_apply_fixups();

[Severity: Medium]
Will calling screen_info_apply_fixups() unconditionally in
vga_arb_device_init() fail to link when CONFIG_PCI=y, CONFIG_VGA_ARB=y, and
CONFIG_SCREEN_INFO=n?

In drivers/pci/Kconfig, VGA_ARB only selects SCREEN_INFO on x86:

drivers/pci/Kconfig:
	config VGA_ARB
		bool "VGA Arbitration" if EXPERT
		default y
		depends on !S390
		select SCREEN_INFO if X86

which matches the CONFIG_X86 guard in vga_is_firmware_default():

drivers/pci/vgaarb.c:vga_is_firmware_default() {
#if defined CONFIG_X86
	return pdev == screen_info_pci_dev(&sysfb_primary_display.screen);
#else
	return false;
#endif
}

However, include/linux/screen_info.h declares screen_info_apply_fixups() as an
external function whenever CONFIG_PCI is enabled, while
drivers/video/Makefile only builds screen_info_pci.o when CONFIG_SCREEN_INFO
is enabled:

include/linux/screen_info.h:
#if defined(CONFIG_PCI)
void screen_info_apply_fixups(void);
struct pci_dev *screen_info_pci_dev(const struct screen_info *si);
#else
static inline void screen_info_apply_fixups(void)
{ }

drivers/video/Makefile:
obj-$(CONFIG_SCREEN_INFO)         += screen_info.o
...
screen_info-$(CONFIG_PCI)         += screen_info_pci.o

On non-x86 architectures with CONFIG_PCI=y, CONFIG_VGA_ARB=y, and
CONFIG_SCREEN_INFO=n, doesn't this result in an undefined reference to
screen_info_apply_fixups()?

[Severity: High]
Also, is subsys_initcall_sync(vga_arb_device_init) the right place in the
initcall sequence to call screen_info_apply_fixups()?

Upstream vga_is_firmware_default() in drivers/pci/vgaarb.c only calls
screen_info_pci_dev() under CONFIG_X86. On x86, subsys_initcall(pci_subsys_init)
runs pcibios_resource_survey() -> pcibios_allocate_dev_resources(). When the
firmware framebuffer BAR has a resource conflict and awaits reassignment,
pcibios_allocate_dev_resources() saves the firmware address and resets
r->start to 0 while keeping resource_size(r) intact:

arch/x86/pci/i386.c:pcibios_allocate_dev_resources() {
	...
	/* We'll assign a new address later */
	pcibios_save_fw_addr(dev, idx, r->start);
	r->end -= r->start;
	r->start = 0;
	...
}

The new BAR address on x86 is not assigned until
fs_initcall(pcibios_assign_resources) -> pci_assign_unassigned_resources(),
which runs after subsys_initcall_sync(vga_arb_device_init).

When screen_info_apply_fixups() runs at subsys_initcall_sync while a
conflicting BAR has pr->start == 0, pr->start != screen_info_lfb_res_start is
true and __screen_info_relocation_is_valid(si, pr) succeeds because
resource_size(pr) is unchanged:

drivers/video/screen_info_pci.c:screen_info_apply_fixups() {
	if (screen_info_lfb_pdev) {
		struct resource *pr = &screen_info_lfb_pdev->resource[screen_info_lfb_bar];

		if (pr->start != screen_info_lfb_res_start) {
			if (__screen_info_relocation_is_valid(si, pr)) {
				__screen_info_set_lfb_base(si, pr->start + screen_info_lfb_offset);
				pr_info("Relocating firmware framebuffer to offset %pa[d] within %pr\n",
					&screen_info_lfb_offset, pr);
			}
			...
		}
	}
}

Wouldn't this clobber si->lfb_base to 0 + screen_info_lfb_offset with a
[mem 0x00000000-...] message before fs_initcall(pcibios_assign_resources)
assigns the actual BAR address, while still failing to match in
vga_is_firmware_default()?

Similarly, for PCI host bridges probed at device_initcall via
pci_host_probe(), vga_arb_device_init() runs before the PCI bus is scanned
and before VGA devices are added via pci_notify().

Finally, since screen_info_apply_fixups() does not update
screen_info_lfb_res_start or clear screen_info_lfb_pdev after applying the
fixup, won't calling it in both vga_arb_device_init() and
device_initcall(sysfb_init) in drivers/firmware/sysfb.c cause the relocation
and log messages to run twice?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261028094634.766723-1-wuqianhai@loongson.cn?part=1

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[Bjorn Helgaas]

On Wed, Oct 28, 2026 at 05:46:34PM +0800, wuqianhai@loongson.cn wrote:
> From: wuqianhai <wuqianhai@loongson.cn>
> 
> PCI resource assignment can relocate the firmware framebuffer BAR, which
> leaves the base address in screen_info stale.  The VGA arbiter then calls
> screen_info_pci_dev() from vga_is_firmware_default(), which fails to match
> the framebuffer against any PCI device's BARs.  As a result, the boot VGA
> device is not recognized and the arbiter may select the wrong default
> device.
> 
> Fix this by calling screen_info_apply_fixups() in vga_arb_device_init()
> before adding the VGA devices.  This relocates lfb_base to the assigned
> BAR address so that vga_is_firmware_default() matches the boot device
> again.
> 
> Tested on a LoongArch platform, with vga_is_firmware_default()
> additionally enabled for CONFIG_LOONGARCH via local changes.
> 
> Fixes: 337bf13aa9ddab8ae47f2677ab75cf69ae33437b ("PCI/VGA: Replace vga_is_firmware_default() with a screen info check")
> Signed-off-by: wuqianhai <wuqianhai@loongson.cn>
> ---
>  drivers/pci/vgaarb.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
> index 3e58b2c05c85..aca594651f58 100644
> --- a/drivers/pci/vgaarb.c
> +++ b/drivers/pci/vgaarb.c
> @@ -1527,6 +1527,14 @@ static int __init vga_arb_device_init(void)
>  	int rc;
>  	struct pci_dev *pdev;
>  
> +	/*
> +	 * PCI resource assignment may have relocated the firmware
> +	 * framebuffer BAR. Update screen_info's lfb_base so that
> +	 * vga_is_firmware_default() can match it against the boot
> +	 * device's relocated resource.
> +	 */
> +	screen_info_apply_fixups();

I'm really confused about this.  vga_is_firmware_default() relies on
screen_info_pci_dev(&sysfb_primary_display.screen):

  vga_is_firmware_default
    screen_info_pci_dev(&sysfb_primary_display.screen)
      numres = screen_info_resources(&sysfb_primary_display.screen, res, ...)
      for (i = 0; i < numres; ++i)
        pdev = __screen_info_pci_dev(&res[i])

screen_info_resources() returns resource structs with PCI bus
addresses in them.  These are not valid CPU addresses, so that seems
broken on any system where bus addresses are not the same as CPU
addresses.

screen_info_fixup_lfb() and screen_info_apply_fixups() may fix the
issue you see, but I think the way this happens is questionable.

screen_info_fixup_lfb() captures the framebuffer PCI bus address in
screen_info_lfb_res_start.  Then screen_info_apply_fixups() compares
that PCI bus address with the CPU address in pdev->resource[].  That's
broken on any system where bus addresses are not the same as CPU
addresses.  I think it's also broken because screen_info_lfb_res_start
may not be at the beginning of the BAR.

I think screen_info_fixup_lfb() should only capture the pci_dev, the
BAR number, and the framebuffer offset into the BAR.  When we need the
CPU or bus address, we can always compute it from those values.

>  	rc = misc_register(&vga_arb_device);
>  	if (rc < 0)
>  		pr_err("error %d registering device\n", rc);
> -- 
> 2.34.1
> 

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[wuqianhai]

Hi Bjorn,

Thanks for the detailed analysis.

You're right that screen_info_fixup_lfb()/screen_info_apply_fixups()
stores a PCI bus address in screen_info_lfb_res_start and compares it
with the CPU address in pdev->resource[].start, which is broken on
systems where bus and CPU addresses differ.

On LoongArch, though, bus and CPU addresses are identical: with modern
firmware, acpi_prepare_root_resources() takes the PCIH path and leaves
the window offset at 0 (see commit 49f33840dcc9).  So the existing
screen_info_apply_fixups() works correctly for LoongArch, and the
address-space confusion you describe does not trigger there.

I've sent a v2 that:
- enables vga_is_firmware_default() for LoongArch,
- restricts the screen_info_apply_fixups() call to LoongArch so x86 and
  other architectures are unaffected,
- makes VGA_ARB select SYSFB on LoongArch to avoid the undefined
  reference when CONFIG_SCREEN_INFO is not set.

The general bus != CPU problem in screen_info_pci.c is still worth
fixing for ARM and friends, but I'd rather keep that separate from this
LoongArch enablement.  Happy to help with that follow-up if useful.

Regards,
wuqianhai

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[Bjorn Helgaas]

[+ Loongson folks]

On Thu, Oct 29, 2026 at 11:39:14AM +0800, wuqianhai@loongson.cn wrote:
> Hi Bjorn,
> 
> Thanks for the detailed analysis.
> 
> You're right that screen_info_fixup_lfb()/screen_info_apply_fixups()
> stores a PCI bus address in screen_info_lfb_res_start and compares it
> with the CPU address in pdev->resource[].start, which is broken on
> systems where bus and CPU addresses differ.
> 
> On LoongArch, though, bus and CPU addresses are identical: with modern
> firmware, acpi_prepare_root_resources() takes the PCIH path and leaves
> the window offset at 0 (see commit 49f33840dcc9).  

This is a tangent from the framebuffer question, but what in the world
is 49f33840dcc9 ("LoongArch: Use per-root-bridge PCIH flag to skip mem
resource fixup") doing?  I see that if "PCIH" is non-zero, it skips
some mem resource "fixup" that was added by 57fc7323a8e7 ("LoongArch:
Add PCI controller support").

But I don't understand why that fixup is there in the first place.
Evidently it takes the upper 24 bits of the MCFG address and ORs it
into window addresses from host bridge _CRS?  That sounds nuts.  It
sounds like the ACPI _CRS is just broken.

The struct resource_entry.offset is the offset between PCI bus
addresses and CPU addresses, so entry->offset being non-zero implies
they are NOT identical, at least on non-PCIH platforms.  And if you
have to hack up the offset from the MCFG address, it sounds like the
_CRS entries are missing the _TRA that is supposed to provide the
offset.

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[Thomas Zimmermann]

Hi

Am 29.10.26 um 00:15 schrieb Bjorn Helgaas:
> On Wed, Oct 28, 2026 at 05:46:34PM +0800, wuqianhai@loongson.cn wrote:
>> From: wuqianhai <wuqianhai@loongson.cn>
>>
>> PCI resource assignment can relocate the firmware framebuffer BAR, which
>> leaves the base address in screen_info stale.  The VGA arbiter then calls
>> screen_info_pci_dev() from vga_is_firmware_default(), which fails to match
>> the framebuffer against any PCI device's BARs.  As a result, the boot VGA
>> device is not recognized and the arbiter may select the wrong default
>> device.
>>
>> Fix this by calling screen_info_apply_fixups() in vga_arb_device_init()
>> before adding the VGA devices.  This relocates lfb_base to the assigned
>> BAR address so that vga_is_firmware_default() matches the boot device
>> again.
>>
>> Tested on a LoongArch platform, with vga_is_firmware_default()
>> additionally enabled for CONFIG_LOONGARCH via local changes.
>>
>> Fixes: 337bf13aa9ddab8ae47f2677ab75cf69ae33437b ("PCI/VGA: Replace vga_is_firmware_default() with a screen info check")
>> Signed-off-by: wuqianhai <wuqianhai@loongson.cn>
>> ---
>>   drivers/pci/vgaarb.c | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
>> index 3e58b2c05c85..aca594651f58 100644
>> --- a/drivers/pci/vgaarb.c
>> +++ b/drivers/pci/vgaarb.c
>> @@ -1527,6 +1527,14 @@ static int __init vga_arb_device_init(void)
>>   	int rc;
>>   	struct pci_dev *pdev;
>>   
>> +	/*
>> +	 * PCI resource assignment may have relocated the firmware
>> +	 * framebuffer BAR. Update screen_info's lfb_base so that
>> +	 * vga_is_firmware_default() can match it against the boot
>> +	 * device's relocated resource.
>> +	 */
>> +	screen_info_apply_fixups();
> I'm really confused about this.  vga_is_firmware_default() relies on
> screen_info_pci_dev(&sysfb_primary_display.screen):
>
>    vga_is_firmware_default
>      screen_info_pci_dev(&sysfb_primary_display.screen)
>        numres = screen_info_resources(&sysfb_primary_display.screen, res, ...)
>        for (i = 0; i < numres; ++i)
>          pdev = __screen_info_pci_dev(&res[i])
>
> screen_info_resources() returns resource structs with PCI bus
> addresses in them.  These are not valid CPU addresses, so that seems
> broken on any system where bus addresses are not the same as CPU
> addresses.

What we get from the firmware for the framebuffer is a memory range.  
  If the underlying PCI memory gets relocated during the boot, we need 
to update the framebuffer data accordingly. This has worked well for the 
last 20 yrs.


>
> screen_info_fixup_lfb() and screen_info_apply_fixups() may fix the
> issue you see, but I think the way this happens is questionable.

>
> screen_info_fixup_lfb() captures the framebuffer PCI bus address in
> screen_info_lfb_res_start.  Then screen_info_apply_fixups() compares
> that PCI bus address with the CPU address in pdev->resource[].  That's
> broken on any system where bus addresses are not the same as CPU
> addresses.  I think it's also broken because screen_info_lfb_res_start
> may not be at the beginning of the BAR.
>
> I think screen_info_fixup_lfb() should only capture the pci_dev, the
> BAR number, and the framebuffer offset into the BAR.  When we need the
> CPU or bus address, we can always compute it from those values.

This is not sufficient, I think. We did this until a while ago and got 
problems with relocated bars. IIRC aarch64 had a number of affected 
systems. See commit 2f29b5c23101 ("video: screen_info: Relocate 
framebuffers behind PCI bridges") for details.

I'm happy to improve that code though, if we can do something better.

Best regards
Thomas

>
>>   	rc = misc_register(&vga_arb_device);
>>   	if (rc < 0)
>>   		pr_err("error %d registering device\n", rc);
>> -- 
>> 2.34.1
>>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[kernel test robot]

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus linus/master v7.3 next-20261028]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/wuqianhai-loongson-cn/PCI-VGA-Fix-boot-device-detection-after-framebuffer-relocation/20261028-174634
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20261028094634.766723-1-wuqianhai%40loongson.cn
patch subject: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation
config: loongarch-allnoconfig (https://download.01.org/0day-ci/archive/20261029/202610291418.tlsEIHSu-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261029/202610291418.tlsEIHSu-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202610291418.tlsEIHSu-lkp@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: screen_info_apply_fixups
   >>> referenced by vgaarb.c
   >>>               drivers/pci/vgaarb.o:(vga_arb_device_init) in archive vmlinux.a

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0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation

[kernel test robot]

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus linus/master v7.3 next-20261028]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/wuqianhai-loongson-cn/PCI-VGA-Fix-boot-device-detection-after-framebuffer-relocation/20261028-174634
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20261028094634.766723-1-wuqianhai%40loongson.cn
patch subject: [PATCH] PCI/VGA: Fix boot device detection after framebuffer relocation
config: microblaze-defconfig (https://download.01.org/0day-ci/archive/20261029/202610292159.Ls5pkJAS-lkp@intel.com/config)
compiler: microblaze-linux-gcc (GCC) 16.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261029/202610292159.Ls5pkJAS-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202610292159.Ls5pkJAS-lkp@intel.com/

All errors (new ones prefixed by >>):

   microblaze-linux-ld: drivers/pci/vgaarb.o: in function `vga_arb_device_init':
>> drivers/pci/vgaarb.c:1536:(.init.text+0x10): undefined reference to `screen_info_apply_fixups'


vim +1536 drivers/pci/vgaarb.c

  1524	
  1525	static int __init vga_arb_device_init(void)
  1526	{
  1527		int rc;
  1528		struct pci_dev *pdev;
  1529	
  1530		/*
  1531		 * PCI resource assignment may have relocated the firmware
  1532		 * framebuffer BAR. Update screen_info's lfb_base so that
  1533		 * vga_is_firmware_default() can match it against the boot
  1534		 * device's relocated resource.
  1535		 */
> 1536		screen_info_apply_fixups();

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0-DAY CI Kernel Test Service
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