Re: [PATCH] PCI: handle pci_sriov_set_totalvfs(dev, 0)

[Edward Cree <ecree@solarflare.com>]

On 31/07/14 18:55, Alexander Duyck wrote:
> It sounds reasonable.  My only real concern is the fact that the error
> reported when attempting to enable the interface will be a ERANGE when
> really a more appropriate error return might be something like a EBUSY
> since it is the vswitch that is occupied.
>
> You might want to take a look at modifying sriov_numvfs_store so that if
> the only option is 0 you return EBUSY for all non-zero values requested.
>  This way it will be more in sync with how we handle the case of
> attempting to update the number of VFs when SR-IOV is already enabled.
Seems mostly reasonable for sfc, but I wonder if EBUSY would necessarily
be appropriate for all devices.  Other devices might have other reasons
why their driver_max_VFs is zero.
So I think it's best to leave it as ERANGE - the proximate reason why
numvfs can't be set is because totalvfs is 0; for the reason why
totalvfs is 0, user can look at the logs.
But I'm open to being persuaded otherwise.

-Edward
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