[PATCH v9 8/9] fbcon: Use screen info to find primary device

[Bjorn Helgaas]

On Thu, Jul 17, 2025 at 12:38:11PM -0500, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello at 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.

This relies on screen_info, which I think is an x86 BIOS-ism.  Isn't
there a UEFI console path?  How does that compare with this?  Is that
relevant or is it something completely different?

>  bool video_is_primary_device(struct device *dev)
>  {
> +#ifdef CONFIG_SCREEN_INFO
> +	struct screen_info *si = &screen_info;
> +#endif
>  	struct pci_dev *pdev;
>  
>  	if (!dev_is_pci(dev))
> @@ -34,7 +38,18 @@ 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;
> +
> +#ifdef CONFIG_SCREEN_INFO
> +	if (pdev == screen_info_pci_dev(si))
> +		return true;
> +#endif
> +
> +	return false;
>  }
>  EXPORT_SYMBOL(video_is_primary_device);
>  
> -- 
> 2.43.0
>