Subject: Re: [net-next 08/15] i40e: acknowledge VFLR when disabling SR-IOV

From: Sergei Shtylyov <[email-masked]>
Date: Mon, 06 Jan 2014 20:43:24 +0400

On 06.01.2014 16:30, Jeff Kirsher wrote:

> From: Mitch Williams <[email-masked]>

> When SR-IOV is disabled, the (now nonexistent) virtual function
> devices undergo a VFLR event. We don't need to handle this event
> because the VFs are gone, but we do need to tell the HW that they are
> complete. This fixes an issue with a phantom VFLR and broken VFs when
> SR-IOV is re-enabled.

> Change-Id: I7580b49ded0158172a85b14661ec212af77000c8
> Signed-off-by: Mitch Williams <[email-masked]>
> Signed-off-by: Jesse Brandeburg <[email-masked]>
> Tested-by: Sibai Li <[email-masked]>
> Signed-off-by: Jeff Kirsher <[email-masked]>
> ---
>   drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 15 +++++++++++++--
>   1 file changed, 13 insertions(+), 2 deletions(-)

> diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> index f92404c..e91f9d7 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
[...]
> @@ -748,8 +750,17 @@ void i40e_free_vfs(struct i40e_pf *pf)
>   	kfree(pf->vf);
>   	pf->vf = NULL;
>
> -	if (!i40e_vfs_are_assigned(pf))
> +	if (!i40e_vfs_are_assigned(pf)) {
>   		pci_disable_sriov(pf->pdev);
> +		/* Acknowledge VFLR for all VFS. Without this, VFs will fail to
> +		 * work correctly when SR-IOV gets re-enabled.
> +		 */
> +		for (vf_id = 0; vf_id < tmp; vf_id++) {
> +			reg_idx = (hw->func_caps.vf_base_id + vf_id) / 32;
> +			bit_idx = (hw->func_caps.vf_base_id + vf_id) % 32;
> +			wr32(hw, I40E_GLGEN_VFLRSTAT(reg_idx), (1 << bit_idx));
> +		}
> +	}
>   	else

    } and *else* should be on the same line. And the *else* arm should also 
have {} now.

>   		dev_warn(&pf->pdev->dev,
>   			 "unable to disable SR-IOV because VFs are assigned.\n");

WBR, Sergei