Re: [PATCH v2] examples/multi_process: reconfigure port when rss or csum isn't supported

[Bruce Richardson <bruce.richardson@intel.com>]

On Mon, Feb 21, 2022 at 03:35:18PM +0000, Wenwu Ma wrote:
> The default values of rx mq_mode and rx offloads for port
> will cause symmetric_mp startup failure if the port do not
> support rss or csum. This Patch make the app to reconfigure
> the NIC without them. Only quit the app if the second
> reconfiguration fails.
> 
> Signed-off-by: Wenwu Ma <wenwux.ma@intel.com>
> ---
>  examples/multi_process/symmetric_mp/main.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/examples/multi_process/symmetric_mp/main.c b/examples/multi_process/symmetric_mp/main.c
> index 050337765f..c0e7ed70e0 100644
> --- a/examples/multi_process/symmetric_mp/main.c
> +++ b/examples/multi_process/symmetric_mp/main.c
> @@ -232,6 +232,20 @@ smp_port_init(uint16_t port, struct rte_mempool *mbuf_pool,
>  	}
>  
>  	retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
> +	if (retval == -EINVAL) {
> +		printf("Maybe port %u don't have csum offloads capabilities, "
> +			"so clear csum config and try again.\n", port);

Two comments for here and below:
1. Don't split error messages across multiple lines, as it means the
user/developer cannot find them using "grep" on the code.
2. Text should try and be shorter and clearer. I'd suggest:
"Port configuration failed. Re-attempting with HW checksum disabled"


> +		port_conf.rxmode.offloads &= ~(RTE_ETH_RX_OFFLOAD_CHECKSUM);
> +		retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
> +	}
> +
> +	if (retval == -ENOTSUP) {
> +		printf("Maybe port %u don't support rss, "
> +			"so clear rss config and try again.\n", port);

Same two comments from above apply here.

> +		port_conf.rxmode.mq_mode &= ~(RTE_ETH_MQ_RX_RSS);
> +		retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
> +	}
> +
>  	if (retval < 0)
>  		return retval;
>  
> -- 
> 2.25.1
>