Re: [PATCH v8 1/2] PCI/ERR: Call pci_bus_reset() before calling ->slot_reset() callback

[Kuppuswamy, Sathyanarayanan]

Hi Bjorn,

On 10/26/20 12:37 PM, Kuppuswamy Sathyanarayanan wrote:
> Currently if report_error_detected() or report_mmio_enabled()
> functions requests PCI_ERS_RESULT_NEED_RESET, current
> pcie_do_recovery() implementation does not do the requested
> explicit device reset, but instead just calls the
> report_slot_reset() on all affected devices. Notifying about the
> reset via report_slot_reset() without doing the actual device
> reset is incorrect. So call pci_bus_reset() before triggering
> ->slot_reset() callback.
Any comments on this series?
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> Reviewed-by: Sinan Kaya <okaya@xxxxxxxxxx>
> Reviewed-by: Ashok Raj <ashok.raj@xxxxxxxxx>
> ---
>   Changes since v7:
>    * Rebased on top of v5.10-rc1.
>
>   Changes since v6:
>    * None.
>
>   Changes since v5:
>    * Added Ashok's Reviewed-by tag.
>
>   Changes since v4:
>    * Added check for pci_reset_bus() return value.
>
>   drivers/pci/pcie/err.c | 12 +++++++-----
>   1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index c543f419d8f9..315a4d559c4c 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -152,6 +152,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>   {
>   	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
>   	struct pci_bus *bus;
> +	int ret;
>   
>   	/*
>   	 * Error recovery runs on all subordinates of the first downstream port.
> @@ -181,11 +182,12 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>   	}
>   
>   	if (status == PCI_ERS_RESULT_NEED_RESET) {
> -		/*
> -		 * TODO: Should call platform-specific
> -		 * functions to reset slot before calling
> -		 * drivers' slot_reset callbacks?
> -		 */
> +		ret = pci_reset_bus(dev);
> +		if (ret < 0) {
> +			pci_err(dev, "Failed to reset %d\n", ret);
> +			status = PCI_ERS_RESULT_DISCONNECT;
> +			goto failed;
> +		}
>   		status = PCI_ERS_RESULT_RECOVERED;
>   		pci_dbg(dev, "broadcast slot_reset message\n");
>   		pci_walk_bus(bus, report_slot_reset, &status);

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer