[PATCH] PCI/ERR: handle disconnected devices in report_error_detected

[Sathyanarayanan Kuppuswamy]

Hi,

On 6/1/22 12:40 AM, Christoph Hellwig wrote:
> When a device is already unplugged by pciehp by the time that the AER
> handler is invoked, the PCIe device will lready be in the

/s/lready/already

> pci_channel_io_perm_failure state.  In that case we should simply
> return PCI_ERS_RESULT_DISCONNECT instead of trying to do a state
> transition that will fail.
> 
> Also untangle the state transition failure from the lack of methods to
> improve the debugging output in case it will happen ever again.

Otherwise, it looks good to me.

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy at linux.intel.com>


> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>   drivers/pci/pcie/err.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index 0c5a143025af4..59c90d04a609a 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -55,10 +55,14 @@ static int report_error_detected(struct pci_dev *dev,
>   
>   	device_lock(&dev->dev);
>   	pdrv = dev->driver;
> -	if (!pci_dev_set_io_state(dev, state) ||
> -		!pdrv ||
> -		!pdrv->err_handler ||
> -		!pdrv->err_handler->error_detected) {
> +	if (pci_dev_is_disconnected(dev)) {
> +		vote = PCI_ERS_RESULT_DISCONNECT;
> +	} else if (!pci_dev_set_io_state(dev, state)) {
> +		pci_info(dev, "can't recover (state transition %u -> %u invalid)\n",
> +			dev->error_state, state);
> +		vote = PCI_ERS_RESULT_NONE;
> +	} else if (!pdrv || !pdrv->err_handler ||
> +		   !pdrv->err_handler->error_detected) {
>   		/*
>   		 * If any device in the subtree does not have an error_detected
>   		 * callback, PCI_ERS_RESULT_NO_AER_DRIVER prevents subsequent

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer