[dpdk-dev] [PATCH] net/igc: fix Rx packet size error

Wang, Haiyue haiyue.wang at intel.com
Fri Apr 16 03:57:10 CEST 2021


> -----Original Message-----
> From: Zhang, AlvinX <alvinx.zhang at intel.com>
> Sent: Friday, April 16, 2021 09:14
> To: Wang, Haiyue <haiyue.wang at intel.com>; Guo, Jia <jia.guo at intel.com>
> Cc: dev at dpdk.org; Zhang, AlvinX <alvinx.zhang at intel.com>; stable at dpdk.org
> Subject: [PATCH] net/igc: fix Rx packet size error
> 
> When DEV_RX_OFFLOAD_KEEP_CRC is enabled, the PMD will minus 4 bytes
> of CRC from the size of a packet, but the NIC will strip the CRC
> because the CRC strip bit in DVMOLR register is not cleared. This
> will cause the size of a packet to be 4 bytes less.
> 
> This patch updates the CRC strip bit according to whether
> DEV_RX_OFFLOAD_KEEP_CRC is enabled.
> 
> Fixes: a5aeb2b9e225 ("net/igc: support Rx and Tx")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Alvin Zhang <alvinx.zhang at intel.com>
> ---
>  drivers/net/igc/igc_txrx.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/igc/igc_txrx.c b/drivers/net/igc/igc_txrx.c
> index c0a5d5e..68b102d 100644
> --- a/drivers/net/igc/igc_txrx.c
> +++ b/drivers/net/igc/igc_txrx.c
> @@ -1290,20 +1290,24 @@ int eth_igc_rx_descriptor_status(void *rx_queue, uint16_t offset)
>  	 * This needs to be done after enable.
>  	 */
>  	for (i = 0; i < dev->data->nb_rx_queues; i++) {
> +		uint32_t dvmolr;
> +
>  		rxq = dev->data->rx_queues[i];
>  		IGC_WRITE_REG(hw, IGC_RDH(rxq->reg_idx), 0);
> -		IGC_WRITE_REG(hw, IGC_RDT(rxq->reg_idx),
> -				rxq->nb_rx_desc - 1);
> +		IGC_WRITE_REG(hw, IGC_RDT(rxq->reg_idx), rxq->nb_rx_desc - 1);
> +
> +		dvmolr = IGC_READ_REG(hw, IGC_DVMOLR(rxq->queue_id));
> 
>  		/* strip queue vlan offload */
> -		if (rxq->offloads & DEV_RX_OFFLOAD_VLAN_STRIP) {
> -			uint32_t dvmolr;
> -			dvmolr = IGC_READ_REG(hw, IGC_DVMOLR(rxq->queue_id));
> +		dvmolr = (rxq->offloads & DEV_RX_OFFLOAD_VLAN_STRIP) ?
> +			 (dvmolr | IGC_DVMOLR_STRVLAN) :
> +			 (dvmolr & ~IGC_DVMOLR_STRVLAN);

Just use "if ... else .."to make code readable:

		if (rxq->offloads & DEV_RX_OFFLOAD_VLAN_STRIP)
			dvmolr |= IGC_DVMOLR_STRVLAN;
		else
			dvmolr &= ~IGC_DVMOLR_STRVLAN;


> 
> -			/* If vlan been stripped off, the CRC is meaningless. */

Looks like we need to handle CRC & VLAN_STRIP co-exist issue:
	If user enables VLAN strip, then keep CRC should be rejected,
	and vice versa.

> -			dvmolr |= IGC_DVMOLR_STRVLAN | IGC_DVMOLR_STRCRC;
> -			IGC_WRITE_REG(hw, IGC_DVMOLR(rxq->reg_idx), dvmolr);
> -		}
> +		dvmolr = (offloads & DEV_RX_OFFLOAD_KEEP_CRC) ?
> +			 (dvmolr & ~IGC_DVMOLR_STRCRC) :
> +			 (dvmolr | IGC_DVMOLR_STRCRC);

Just use "if ... else .."to make code readable:

		if (offloads & DEV_RX_OFFLOAD_KEEP_CRC)
			dvmolr &= ~IGC_DVMOLR_STRCRC;
		else
			dvmolr |= IGC_DVMOLR_STRCRC;

> +
> +		IGC_WRITE_REG(hw, IGC_DVMOLR(rxq->reg_idx), dvmolr);
>  	}
> 
>  	return 0;
> --
> 1.8.3.1



More information about the dev mailing list