From: Mario Limonciello <mario.limonciello@amd.com>

On systems with non VGA GPUs fbcon can't find the primary GPU because
video_is_primary_device() only checks the VGA arbiter.

Add a screen info check to video_is_primary_device() so that callers
can get accurate data on such systems.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v5:
 * Only change video-common.c
v4:
 * use helper
---
 arch/x86/video/video-common.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/x86/video/video-common.c b/arch/x86/video/video-common.c
index 81fc97a2a837a..917568e4d7fb1 100644
--- a/arch/x86/video/video-common.c
+++ b/arch/x86/video/video-common.c
@@ -9,6 +9,7 @@
 
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/screen_info.h>
 #include <linux/vgaarb.h>
 
 #include <asm/video.h>
@@ -27,6 +28,7 @@ EXPORT_SYMBOL(pgprot_framebuffer);
 
 bool video_is_primary_device(struct device *dev)
 {
+	struct screen_info *si = &screen_info;
 	struct pci_dev *pdev;
 
 	if (!dev_is_pci(dev))
@@ -34,7 +36,16 @@ bool video_is_primary_device(struct device *dev)
 
 	pdev = to_pci_dev(dev);
 
-	return (pdev == vga_default_device());
+	if (!pci_is_display(pdev))
+		return false;
+
+	if (pdev == vga_default_device())
+		return true;
+
+	if (pdev == screen_info_pci_dev(si))
+		return true;
+
+	return false;
 }
 EXPORT_SYMBOL(video_is_primary_device);
 
-- 
2.43.0

Hi Mario,

kernel test robot noticed the following build errors:

[auto build test ERROR on pci/next]
[also build test ERROR on pci/for-linus tiwai-sound/for-next tiwai-sound/for-linus tip/x86/core linus/master v6.16-rc6 next-20250714]
[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/Mario-Limonciello/PCI-Add-helper-for-checking-if-a-PCI-device-is-a-display-controller/20250706-223745
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20250706143613.1972252-9-superm1%40kernel.org
patch subject: [PATCH v7 8/9] fbcon: Use screen info to find primary device
config: i386-randconfig-053-20250714 (https://download.01.org/0day-ci/archive/20250714/202507142313.iWVTOSVB-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250714/202507142313.iWVTOSVB-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/202507142313.iWVTOSVB-lkp@intel.com/

All errors (new ones prefixed by >>):

   ld: arch/x86/video/video-common.o: in function `video_is_primary_device':
>> arch/x86/video/video-common.c:45: undefined reference to `screen_info_pci_dev'


vim +45 arch/x86/video/video-common.c

    28	
    29	bool video_is_primary_device(struct device *dev)
    30	{
    31		struct screen_info *si = &screen_info;
    32		struct pci_dev *pdev;
    33	
    34		if (!dev_is_pci(dev))
    35			return false;
    36	
    37		pdev = to_pci_dev(dev);
    38	
    39		if (!pci_is_display(pdev))
    40			return false;
    41	
    42		if (pdev == vga_default_device())
    43			return true;
    44	
  > 45		if (pdev == screen_info_pci_dev(si))
    46			return true;
    47	
    48		return false;
    49	}
    50	EXPORT_SYMBOL(video_is_primary_device);
    51	

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