Subject: RE: [PATCH v4 bpf-next 03/10] ice: check DD bit on Rx descriptor rather than (EOP | RS)

From: John Fastabend <[email-masked]>
Date: Fri, 17 Jun 2022 18:58:57 -0700

Maciej Fijalkowski wrote:
> Tx side sets EOP and RS bits on descriptors to indicate that a
> particular descriptor is the last one and needs to generate an irq when
> it was sent. These bits should not be checked on completion path
> regardless whether it's the Tx or the Rx. DD bit serves this purpose and
> it indicates that a particular descriptor is either for Rx or was
> successfully Txed.
> 
> Look at DD bit being set in ice_lbtest_receive_frames() instead of EOP
> and RS pair.
> 
> Signed-off-by: Maciej Fijalkowski <[email-masked]>

Is this a bugfix? If so it should go to bpf tree.

> ---
>  drivers/net/ethernet/intel/ice/ice_ethtool.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> index 1e71b70f0e52..b6275a29fa0d 100644
> --- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
> +++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
> @@ -658,7 +658,7 @@ static int ice_lbtest_receive_frames(struct ice_rx_ring *rx_ring)
>  		rx_desc = ICE_RX_DESC(rx_ring, i);
>  
>  		if (!(rx_desc->wb.status_error0 &
> -		    cpu_to_le16(ICE_TX_DESC_CMD_EOP | ICE_TX_DESC_CMD_RS)))
> +		    cpu_to_le16(BIT(ICE_RX_FLEX_DESC_STATUS0_DD_S))))
>  			continue;
>  
>  		rx_buf = &rx_ring->rx_buf[i];
> -- 
> 2.27.0
>