Re: [dpdk-stable] [dpdk-dev] [PATCH v2] ethdev: fix data type for port id

[Thomas Monjalon <thomas@monjalon.net>]

27/10/2020 14:41, wangyunjian:
> From: Yunjian Wang <wangyunjian@huawei.com>
> 
> The ethdev port id should be 16 bits now. This patch fixes the data
> type of the variable for 'pid', changing from uint32_t to uint16_t.
> 
> We also need use RTE_BUILD_BUG_ON() to ensure that RTE_MAX_ETHPORTS
> is less or equal to UINT16_MAX.

Actually the need is to check that we have room for an increment
after RTE_MAX_ETHPORTS, meaning RTE_MAX_ETHPORTS < UINT16_MAX.

> Fixes: 5b7ba31148a8 ("ethdev: add port ownership")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> ---
> v2:
>    add RTE_BUILD_BUG_ON() check for RTE_MAX_ETHPORTS validity
> ---
>  rte_eth_dev_get_port_by_name(const char *name, uint16_t *port_id)
>  {
> -	uint32_t pid;
> +	uint16_t pid;
>  
>  	if (name == NULL) {
>  		RTE_ETHDEV_LOG(ERR, "Null pointer is specified\n");
> @@ -4292,6 +4292,8 @@ RTE_INIT(eth_dev_init_cb_lists)
>  {
>  	int i;
>  
> +	RTE_BUILD_BUG_ON(RTE_MAX_ETHPORTS > UINT16_MAX);

As explained above, should check >=

This check is global for ethdev.
Please could you move it somewhere else?