[PATCH] cxl: Route eeh events to all slices for pci_channel_io_perm_failure state

[Andrew Donnellan]

On 22/02/17 21:51, Vaibhav Jain wrote:
> Fix a boundary condition where in some cases an eeh event with
> state == pci_channel_io_perm_failure wont be passed on to a driver
> attached to the virtual pci device associated with a slice. This will
> happen in case the slice just before (n-1) doesn't have any vph bus

s/vph/vPHB/?

> associated with it, that results in an early return from
> cxl_pci_error_detected callback.
>
> This also simplifies branch that handles this eeh state by returning
> PCI_ERS_RESULT_DISCONNECTED in all cases as the adapter is will be
> removed irrespective of the return value of cxl_pci_error_detected
> callback.

Agree with Matthew that this could be simplified a bit. If I'm 
interpreting this correctly, we could reword it something like:

"As the adapter will be removed irrespective of the return value of 
cxl_vphb_error_detected(), return PCI_ERS_RESULT_DISCONNECT in all 
cases, even if the AFU isn't using a vPHB (in which case we currently 
return PCI_ERS_RESULT_NONE)."

>
> Fixes: e4f5fc001a6("cxl: Do not create vPHB if there are no AFU configuration records")
> Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>

Fix looks reasonable to me!

Reviewed-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>

> ---
>  drivers/misc/cxl/pci.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
> index 80a87ab..679afc9 100644
> --- a/drivers/misc/cxl/pci.c
> +++ b/drivers/misc/cxl/pci.c
> @@ -1780,15 +1780,13 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
>
>  	/* If we're permanently dead, give up. */
>  	if (state == pci_channel_io_perm_failure) {
> -		/* Tell the AFU drivers; but we don't care what they
> -		 * say, we're going away.
> -		 */
>  		for (i = 0; i < adapter->slices; i++) {
>  			afu = adapter->afu[i];
> -			/* Only participate in EEH if we are on a virtual PHB */
> -			if (afu->phb == NULL)
> -				return PCI_ERS_RESULT_NONE;
> -			cxl_vphb_error_detected(afu, state);
> +			/* Tell the AFU drivers; but we don't care what they
> +			 * say, we're going away.
> +			 */
> +			if (afu->phb != NULL)
> +				cxl_vphb_error_detected(afu, state);
>  		}
>  		return PCI_ERS_RESULT_DISCONNECT;
>  	}
>

-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan at au1.ibm.com  IBM Australia Limited