Re: [PATCH v2 1/1] MIPS: Malta: Use pcibios_align_resource() to block io range

[Guenter Roeck]

On 10/17/25 15:12, Bjorn Helgaas wrote:
> On Fri, Oct 17, 2025 at 02:09:03PM +0300, Ilpo Järvinen wrote:
> > According to Maciej W. Rozycki <macro@xxxxxxxxxxx>, the
> > mips_pcibios_init() for malta adjusts root bus IO resource start
> > address to prevent interfering with PIIX4 I/O cycle decoding. Adjusting
> > lower bound leaves PIIX4 IO resources outside of the root bus resource
> > and assign_fixed_resource_on_bus() does not link the resources into the
> > resource tree.
> >
> > Prior to commit ae81aad5c2e1 ("MIPS: PCI: Use pci_enable_resources()")
> > the arch specific pcibios_enable_resources() did not check if the
> > resources were assigned which diverges from what PCI core checks,
> > effectively hiding the PIIX4 IO resources were not properly within the
> > resource tree. After starting to use pcibios_enable_resources() from
> > PCI core, enabling PIIX4 fails:
> >
> > ata_piix 0000:00:0a.1: BAR 0 [io  0x01f0-0x01f7]: not claimed; can't enable device
> > ata_piix 0000:00:0a.1: probe with driver ata_piix failed with error -22
> >
> > MIPS PCI code already has support for enforcing lower bounds using
> > PCIBIOS_MIN_IO in pcibios_align_resource() without altering the IO
> > window start address itself. Make malta PCI code too to use
> > PCIBIOS_MIN_IO.
> >
> > Fixes: ae81aad5c2e1 ("MIPS: PCI: Use pci_enable_resources()")
> > Fixes: aa0980b80908 ("Fixes for system controllers for Atlas/Malta core cards.")
> > Link: https://lore.kernel.org/linux-pci/9085ab12-1559-4462-9b18-f03dcb9a4088@xxxxxxxxxxxx/
> > Link: https://lore.kernel.org/linux-pci/alpine.DEB.2.21.2510132229120.39634@xxxxxxxxxxxxxxxxx/
> > Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > Suggested-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
> > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
>
> Since ae81aad5c2e1 ("MIPS: PCI: Use pci_enable_resources()") came
> through the PCI tree, I'd be happy to merge this as well, given your
> ack, Thomas.  It would be ideal to have a tested-by from Guenter.

I'll run it through my testbed tonight.

Guenter