Re: [PATCH v4] PCI: Disable broken FLR on MediaTek MT7925

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The FLR disable quirk for the MediaTek MT7925 is incomplete as it misses the alternative PCI device ID 0x0717.
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commit 05ad422b1a9dbfc144c4f93e78328e8fa0ea98dc
Author: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

PCI: Disable broken FLR on MediaTek MT7925

This commit disables Function Level Reset (FLR) for the MediaTek MT7925
device by adding a quirk for device ID 0x7925. This prevents the device
from becoming unrecoverable after an unclean VM shutdown in VFIO passthrough
scenarios.

> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index caaed1a01dc02..e49136ac5dbfb 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -5605,6 +5605,7 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x443, quirk_intel_qat_vf_cap);
>   * Intel 82579LM Gigabit Ethernet Controller 0x1502
>   * Intel 82579V Gigabit Ethernet Controller 0x1503
>   * Mediatek MT7922 802.11ax PCI Express Wireless Network Adapter
> + * Mediatek MT7925 802.11be PCI Express Wireless Network Adapter
>   */
>  static void quirk_no_flr(struct pci_dev *dev)
>  {

[ ... ]

> @@ -5619,6 +5620,7 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x17f0, quirk_no_flr);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_no_flr);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_no_flr);
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_MEDIATEK, 0x0616, quirk_no_flr);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_MEDIATEK, 0x7925, quirk_no_flr);

[Severity: High]
This isn't a bug introduced by this patch, but the FLR disable quirk for the
MT7925 appears to be missing an alternative device ID.

Looking at the MT7925 PCI driver, it explicitly binds to two device IDs:

drivers/net/wireless/mediatek/mt76/mt7925/pci.c:mt7925_pci_device_table[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_MEDIATEK, 0x7925),
                .driver_data = (kernel_ulong_t)MT7925_FIRMWARE_WM },
        { PCI_DEVICE(PCI_VENDOR_ID_MEDIATEK, 0x0717),
                .driver_data = (kernel_ulong_t)MT7925_FIRMWARE_WM },
        { },
};

Since both IDs represent the same hardware family and share the same firmware,
could device ID 0x0717 exhibit the exact same broken FLR behavior?

Should 0x0717 be added to the quirk list to prevent it from being permanently
bricked during VM crash recovery?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260522070646.203115-1-jtornosm@redhat.com?part=1