Re: [dpdk-stable] [dpdk-dev] [PATCH v3] ethdev: fix data type for port id

[Thomas Monjalon <thomas@monjalon.net>]

02/11/2020 10:18, wangyunjian:
> From: Yunjian Wang <wangyunjian@huawei.com>
> 
> The ethdev port id is 16 bits now. This patch fixes the data type
> of the variable for 'pid', which changing from uint32_t to uint16_t.
> 
> RTE_MAX_ETHPORTS is the maximum number of ports, which customized by
> the user. To avoid 16-bit unsigned integer overflow, the valid value
> of RTE_MAX_ETHPORTS should be set from 0 to UINT16_MAX, and it is
> safer to cut one more port from space.
> 
> So we use RTE_BUILD_BUG_ON() to ensure that RTE_MAX_ETHPORTS is less
> to UINT16_MAX.
> 
> Fixes: 5b7ba31148a8 ("ethdev: add port ownership")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
> ---
> v3:
>    fix code styles suggested by Thomas Monjalon and Andrew Rybchenko

I don't understand why you add the compile check in several place.
We should just find one good place for checking RTE_MAX_ETHPORTS
at compilation time.

I suggest rte_eth_find_next() or rte_eth_dev_allocate().
Or maybe rte_eth_dev_is_valid_port().

Please choose only one.