Re: [PATCH v3] PCI: Disable ASPM L0s for Realtek RTS525A

[Manivannan Sadhasivam <mani@kernel.org>]

On Mon, Jul 06, 2026 at 10:53:58AM +0800, Max Lee wrote:
> The Realtek RTS525A PCIe card reader reports an AER Correctable Replay
> Timer Timeout storm when ASPM L0s is enabled on its link.  On an affected
> HP ZBook Power 16 inch G11, the Root Port received tens of millions of
> AER interrupts from the RTS525A even when the rtsx_pci driver was
> blacklisted and the endpoint was not enabled by a driver.
> 
> Testing with OS-native AER control showed that disabling only L0s on the
> RTS525A link stops new AER interrupt and counter growth while leaving L1
> enabled.  Disabling L1, L1 substates, or Clock PM alone did not stop the
> storm.
> 
> Prevent the broken L0s configuration by removing L0s from the RTS525A
> advertised ASPM capability.  This avoids enabling the non-working ASPM
> state instead of masking the resulting AER Replay Timer Timeout reports.
> 

If you can add the AER log snippet here, it will help others to find this quirk
in the future.

> Signed-off-by: Max Lee <max.lee@canonical.com>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

One minor nit below...

> ---
> Changes in v3:
>   - Disable ASPM L0s for RTS525A instead of masking AER Replay Timer
>     Timeout reports.
>   - Keep ASPM L1 enabled based on testing that only L0s is required to
>     reproduce the storm.
>   - Drop the endpoint/root-port AER mask quirk from v2.
> 
>  drivers/pci/quirks.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index caaed1a01dc0..e63ed055f466 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -2520,6 +2520,9 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x10f1, quirk_disable_aspm_l0s);
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x10f4, quirk_disable_aspm_l0s);
>  DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1508, quirk_disable_aspm_l0s);
>  
> +/* Realtek RTS525A generates Replay Timer Timeouts when L0s is enabled. */

s/Replay Timer Timeouts/Replay Timer Timeout Storm

to stress the severity.

- Mani

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