Re: [dpdk-dev] [PATCH] net/ice: retry getting VF VSI map after it fails

["Wang, Haiyue" <haiyue.wang@intel.com>]

> -----Original Message-----
> From: Yu, DapengX <dapengx.yu@intel.com>
> Sent: Tuesday, September 14, 2021 11:09
> To: Yang, Qiming <qiming.yang@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>
> Cc: dev@dpdk.org; Wang, Haiyue <haiyue.wang@intel.com>; Yu, DapengX <dapengx.yu@intel.com>;
> stable@dpdk.org
> Subject: [PATCH] net/ice: retry getting VF VSI map after it fails
> 
> From: Dapeng Yu <dapengx.yu@intel.com>
> 
> The request of getting VF VSI map request may fail when DCF is busy,
> this patch adds retry mechanism to make it able to succeed.
> 
> Fixes: b09d34ac8584 ("net/ice: fix flow redirector")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Dapeng Yu <dapengx.yu@intel.com>
> ---
>  drivers/net/ice/ice_dcf.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ice/ice_dcf.c b/drivers/net/ice/ice_dcf.c
> index 38e9a84698..043bd48192 100644
> --- a/drivers/net/ice/ice_dcf.c
> +++ b/drivers/net/ice/ice_dcf.c
> @@ -534,6 +534,7 @@ int
>  ice_dcf_handle_vsi_update_event(struct ice_dcf_hw *hw)
>  {
>  	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(hw->eth_dev);
> +	int i = 0;
>  	int err = 0;
> 
>  	rte_spinlock_lock(&hw->vc_cmd_send_lock);
> @@ -541,8 +542,18 @@ ice_dcf_handle_vsi_update_event(struct ice_dcf_hw *hw)
>  	rte_intr_disable(&pci_dev->intr_handle);
>  	ice_dcf_disable_irq0(hw);
> 
> -	if (ice_dcf_get_vf_resource(hw) || ice_dcf_get_vf_vsi_map(hw) < 0)
> -		err = -1;
> +	do {
> +		if (ice_dcf_get_vf_resource(hw) ||
> +		    ice_dcf_get_vf_vsi_map(hw) < 0) {
> +			err = -1;
> +			goto again;
> +		} else {
> +			err = 0;
> +			break;
> +		}
> +again:
> +		rte_delay_ms(ICE_DCF_ARQ_CHECK_TIME);
> +	} while (i++ < ICE_DCF_ARQ_MAX_RETRIES);
> 

I think we can remove the 'goto', and sleep if we can (like < MAX_RERRIES),
like:

	int err = -1;
	int i = 0;

	for (;;) {
		if (ice_dcf_get_vf_resource(hw) == 0 &&
		    ice_dcf_get_vf_vsi_map(hw) >= 0) {
			err = 0;
			break;
		}

		if (++i < ICE_DCF_ARQ_MAX_RETRIES)
			break;

		rte_delay_ms(ICE_DCF_ARQ_CHECK_TIME);
	}

>  	rte_intr_enable(&pci_dev->intr_handle);
>  	ice_dcf_enable_irq0(hw);
> --
> 2.27.0