On 1/18/2023 6:00 AM, Jiawen Wu wrote:
> When round up buffer size to 1K, to configure the register, hardware will
> receive packets exceeding the buffer size in LRO mode. It will cause a
> segment fault in the receive function.
>
> Fixes: be797cbf4582 ("net/txgbe: add Rx and Tx init")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Jiawen Wu <jiawe...@trustnetic.com>
> ---
> drivers/net/txgbe/txgbe_rxtx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/txgbe/txgbe_rxtx.c b/drivers/net/txgbe/txgbe_rxtx.c
> index ac1bba08a3..ae70ca3beb 100644
> --- a/drivers/net/txgbe/txgbe_rxtx.c
> +++ b/drivers/net/txgbe/txgbe_rxtx.c
> @@ -4382,7 +4382,7 @@ txgbe_dev_rx_init(struct rte_eth_dev *dev)
> */
> buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
> RTE_PKTMBUF_HEADROOM);
> - buf_size = ROUND_UP(buf_size, 0x1 << 10);
> + buf_size = ROUND_DOWN(buf_size, 0x1 << 10);
> srrctl |= TXGBE_RXCFG_PKTLEN(buf_size);
>
What if 'buf_size' is less than 1K, won't 'ROUND_DOWN' make it 0, and I
assume setting 0 to register may cause problem.
And according to the code comment for 'buf_size' [1], buffer size can't
be more than 16K, but technically 'buf_size' can be more than 16K.
Does the HW constrain values larger than 16K? If not the 'buf_size'
value needs to be checked against the 16K limit.
[1]
/*
* Configure the RX buffer size in the PKTLEN field of
* the RXCFG register of the queue.
* The value is in 1 KB resolution. Valid values can be from
* 1 KB to 16 KB.
*/
