Re: [PATCH] PCI: Add PCI ID 12d8:b404 for Pericom switch ACS quirk

[Bjorn Helgaas <helgaas@kernel.org>]

[+cc Nathan, author of acd61ffb2f16 ("PCI: Add ACS quirk for Pericom
PI7C9X2G switches")]

On Mon, Jan 19, 2026 at 05:08:33PM +0100, Nicolas Cavallari wrote:
> 12d8:b404 is apparently another PCI ID for Pericom PI7C9X2G404 (as
> identified by the chip silkscreen and lspci).
> 
> It is also affected by the PI7C9X2G errata (e.g. a network card attached
> to it fails under load when P2P Redirect Request is enabled), so apply
> the same quirk to this PCI ID too.
> 
> PCI bridge [0604]: Pericom Semiconductor PI7C9X2G404 EV/SV PCIe2 4-Port/4-Lane Packet Switch [12d8:b404] (rev 01)
> 
> Fixes: acd61ffb2f16 ("PCI: Add ACS quirk for Pericom PI7C9X2G switches")
> Closes: https://lore.kernel.org/all/a1d926f0-4cb5-4877-a4df-617902648d80@green-communications.fr/
> Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>

Applied to pci/virtualization for v6.20, thanks!

> ---
>  drivers/pci/quirks.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index b9c252aa6fe0..c462d0ed3fd6 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -6188,6 +6188,10 @@ DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_PERICOM, 0x2303,
>  			 pci_fixup_pericom_acs_store_forward);
>  DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_PERICOM, 0x2303,
>  			 pci_fixup_pericom_acs_store_forward);
> +DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_PERICOM, 0xb404,
> +			 pci_fixup_pericom_acs_store_forward);
> +DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_PERICOM, 0xb404,
> +			 pci_fixup_pericom_acs_store_forward);
>  
>  static void nvidia_ion_ahci_fixup(struct pci_dev *pdev)
>  {
> 
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> -- 
> 2.51.0
>