Re: [PATCH] PCI: Mask Replay Timer Timeout for Realtek RTS525A

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The quirk returns early if the endpoint lacks the AER capability, unintentionally skipping the AER mask on the parent root port.
--

commit 33ed73136f45313933a545d6af06c38d893ebef2
Author: Max Lee <max.lee@canonical.com>

PCI: Mask Replay Timer Timeout for Realtek RTS525A

This commit adds a PCI fixup quirk for the Realtek RTS525A SD card reader.
It masks the Replay Timer Timeout on both the endpoint and its parent root
port to prevent an AER storm during PCIe link initialization.

> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index caaed1a01dc02..072d1456daad4 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -6380,4 +6380,23 @@ static void pci_mask_replay_timer_timeout(struct pci_dev *pdev)
>  }
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_GLI, 0x9750, pci_mask_replay_timer_timeout);
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_GLI, 0x9755, pci_mask_replay_timer_timeout);
> +
> +static void pci_mask_replay_timer_timeout_on_endpoint(struct pci_dev *pdev)
> +{
> +	u32 val;
> +
> +	if (!pdev->aer_cap)
> +		return;

[Severity: High]
If the endpoint lacks the AER capability, this early return will entirely
skip masking the parent root port later in the function. Does this leave the
system vulnerable to the AER storm from the parent port if the endpoint's
AER capability is disabled or hidden?

Could this be restructured so that the parent root port masking is still
applied even when the endpoint lacks the AER capability?

> +
> +	pci_info(pdev, "mask Replay Timer Timeout on endpoint due to hardware defect\n");
> +
> +	pci_read_config_dword(pdev, pdev->aer_cap + PCI_ERR_COR_MASK, &val);
> +	val |= PCI_ERR_COR_REP_TIMER;
> +	pci_write_config_dword(pdev, pdev->aer_cap + PCI_ERR_COR_MASK, val);
> +
> +	/* Also mask the parent root port */
> +	pci_mask_replay_timer_timeout(pdev);
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260528032347.644365-1-max.lee@canonical.com?part=1