Re: [PATCH] x86/early-quirks: Scan all functions in early_pci_scan_bus()

[Lukas Wunner]

On Fri, Aug 07, 2026 at 11:46:02AM +0200, Thorsten Blum wrote:
> early_pci_scan_bus() stops scanning a PCI slot when check_dev_quirk()
> returns nonzero, which avoids probing functions 1-7 on single-function
> devices, but also stops scanning when a function is absent on a
> multifunction device.
> 
> This can skip early quirks on multifunction devices with holes in their
> function numbering.
> 
> Check function 0 first, and if it indicates a multifunction device, scan
> functions 1-7 independently so that absent functions do not cause later
> ones to be skipped.

Which device do you need this for?  We should only scan additional
Functions if a quirk needs to applied to them because this extends
boot time.  It requires a justification and shouldn't be done "just
because".

Thanks,

Lukas