On Fri, Mar 27, 2026 at 10:56:43AM +0100, Lukas Wunner wrote:
> When searching for the error source, the AER driver rules out devices
> whose enable_cnt is zero. This was introduced in 2009 by commit
> 28eb27cf0839 ("PCI AER: support invalid error source IDs") without
> providing a rationale.
>
> Drivers typically call pci_enable_device() on probe, hence the enable_cnt
> check essentially filters out unbound devices. At the time of the commit,
> drivers had to opt in to AER by calling pci_enable_pcie_error_reporting()
> and so any AER-enabled device could be assumed to be bound to a driver.
> The check thus made sense because it allowed skipping config space
> accesses to devices which were known not to be the error source.
>
> But since 2022, AER is universally enabled on all devices when they are
> enumerated, cf. commit f26e58bf6f54 ("PCI/AER: Enable error reporting when
> AER is native").
>
> Errors may very well be reported by unbound devices, e.g. due to link
> instability. By ruling them out as error source, errors reported by them
> are neither logged nor cleared. When they do get bound and another error
> occurs, the earlier error is reported together with the new error, which
> may confuse users. Stop doing so.
>
> Fixes: f26e58bf6f54 ("PCI/AER: Enable error reporting when AER is native")
> Signed-off-by: Lukas Wunner <[email protected]>
> Cc: [email protected] # v6.0+
Applied to pci/aer for v7.1, thanks!
> ---
> drivers/pci/pcie/aer.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 4299c55..384d026 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -1039,8 +1039,6 @@ static bool is_error_source(struct pci_dev *dev, struct
> aer_err_info *e_info)
> * 3) There are multiple errors and prior ID comparing fails;
> * We check AER status registers to find possible reporter.
> */
> - if (atomic_read(&dev->enable_cnt) == 0)
> - return false;
>
> /* Check if AER is enabled */
> pcie_capability_read_word(dev, PCI_EXP_DEVCTL, ®16);
> --
> 2.51.0
>
