Subject: Re: [net-next 04/14] i40e: tolerate lost interrupts

From: Sergei Shtylyov <[email-masked]>
Date: Thu, 03 Jul 2014 16:15:19 +0400

Hello.

On 07/03/2014 06:40 AM, Jeff Kirsher wrote:

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

> If the AQ interrupt gets lost for some reason, VF communications will
> stall as the VFs have no way of reaching the PF, which is essentially
> deaf. The VFs end up waiting forever for a reply that will never come.

> To alleviate this condition, go ahead and check the ARQ every time we
> run the service task. Remove the check for a pending event, and get rid
> of a chatty error message that is now meaningless.

> Change-ID: I0fc9d18169cd45c98f60188aef872cd6cee9a027
> Signed-off-by: Mitch Williams <[email-masked]>
> Tested-by: Jim Young <[email-masked]>
> Signed-off-by: Jeff Kirsher <[email-masked]>
> ---
>   drivers/net/ethernet/intel/i40e/i40e_main.c | 8 ++------
>   1 file changed, 2 insertions(+), 6 deletions(-)

> diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
> index 440b671..88704c0 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
[...]
> @@ -5360,10 +5357,9 @@ static void i40e_clean_adminq_subtask(struct i40e_pf *pf)
>   	do {
>   		event.msg_size = I40E_MAX_AQ_BUF_SIZE; /* reinit each time */
>   		ret = i40e_clean_arq_element(hw, &event, &pending);
> -		if (ret == I40E_ERR_ADMIN_QUEUE_NO_WORK) {
> -			dev_info(&pf->pdev->dev, "No ARQ event found\n");
> +		if (ret == I40E_ERR_ADMIN_QUEUE_NO_WORK)
>   			break;
> -		} else if (ret) {
> +		else if (ret) {

    Keep {} around both arms of the *if* statement please, according to the 
kernel coding style.

>   			dev_info(&pf->pdev->dev, "ARQ event error %d\n", ret);
>   			break;
>   		}
>

WBR, Sergei