Re: [PATCH 2/5] PCI/ERR: Fix uevent on failure to recover

[Niklas Schnelle <schnelle@linux.ibm.com>]

On Wed, 2025-08-13 at 07:11 +0200, Lukas Wunner wrote:
> Upon failure to recover from a PCIe error through AER, DPC or EDR, a
> uevent is sent to inform user space about disconnection of the bridge
> whose subordinate devices failed to recover.
> 
> However the bridge itself is not disconnected.  Instead, a uevent should
> be sent for each of the subordinate devices.
> 
> Only if the "bridge" happens to be a Root Complex Event Collector or
> Integrated Endpoint does it make sense to send a uevent for it (because
> there are no subordinate devices).
> 
> Right now if there is a mix of subordinate devices with and without
> pci_error_handlers, a BEGIN_RECOVERY event is sent for those with
> pci_error_handlers but no FAILED_RECOVERY event is ever sent for them
> afterwards.  Fix it.
> 
> Fixes: 856e1eb9bdd4 ("PCI/AER: Add uevents in AER and EEH error/resume")
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> Cc: stable@vger.kernel.org  # v4.16+
> ---
--- snip ---
> 
> +static int report_perm_failure_detected(struct pci_dev *dev, void *data)
> +{
> +	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
> +	return 0;
> +}
> +
>  static int report_mmio_enabled(struct pci_dev *dev, void *data)
>  {
>  	struct pci_driver *pdrv;
> @@ -272,7 +278,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>  failed:
>  	pci_walk_bridge(bridge, pci_pm_runtime_put, NULL);
>  
> -	pci_uevent_ers(bridge, PCI_ERS_RESULT_DISCONNECT);
> +	pci_walk_bridge(bridge, report_perm_failure_detected, NULL);
>  
>  	pci_info(bridge, "device recovery failed\n");
>  

Thanks for catching this during review of my other error recovery
uevent fix! Looks good and I like that you kept the report_*_detected()
naming which makes the mismatched symmetry of the existing code quite
easy to see.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>