Re: [dpdk-dev] [PATCH v3] i40e:Fix the Descriptor Done check mechanism for i40e

["Wu, Jingjing" <jingjing.wu@intel.com>]

Acked-by: Jingjing Wu <jingjing.wu@intel.com>

> -----Original Message-----
> From: Tao, Zhe
> Sent: Thursday, July 09, 2015 10:58 AM
> To: dev@dpdk.org
> Cc: Tao, Zhe; Wu, Jingjing
> Subject: [PATCH v3] i40e:Fix the Descriptor Done check mechanism for i40e
> 
> If a descriptor the device drive is handling is the context descriptor, its type
> value will be 0x1.
> When using the not operator ! to do the conditional check, if the expression
> value is zero, the device driver will consider the transaction for this descriptor
> has been completed, even its DD field is still 0x1 which means NIC has not
> finished the operation on this descriptor.
> Use the 0xF to check the DD status to avoid the above issue happens.
> 
> Signed-off-by: Zhe Tao <zhe.tao@intel.com>
> ---
> 
> Patch v3 changes:
> -Fix typo for the patch
> 
> Patch v2 changes:
> -Fix the DD check mechanism for other functions (besides the
> i40e_xmit_cleanup) which use the DD bits to do conditional check
> 
> changes:
> -Fix the DD check mechanism for i40e_xmit_cleanup
> 
>  drivers/net/i40e/i40e_fdir.c |  3 ++-
>  drivers/net/i40e/i40e_rxtx.c | 10 ++++++----
>  2 files changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/i40e/i40e_fdir.c b/drivers/net/i40e/i40e_fdir.c index
> 4bf98d0..f3cb757 100644
> --- a/drivers/net/i40e/i40e_fdir.c
> +++ b/drivers/net/i40e/i40e_fdir.c
> @@ -1110,7 +1110,8 @@ i40e_fdir_filter_programming(struct i40e_pf *pf,
> 
>  	for (i = 0; i < I40E_FDIR_WAIT_COUNT; i++) {
>  		rte_delay_us(I40E_FDIR_WAIT_INTERVAL_US);
> -		if (txdp->cmd_type_offset_bsz &
> +		if ((txdp->cmd_type_offset_bsz &
> +
> 	rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) ==
> 
> 	rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE))
>  			break;
>  	}
> diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c index
> 2de0ac4..7c0c684 100644
> --- a/drivers/net/i40e/i40e_rxtx.c
> +++ b/drivers/net/i40e/i40e_rxtx.c
> @@ -574,8 +574,9 @@ i40e_xmit_cleanup(struct i40e_tx_queue *txq)
>  		desc_to_clean_to = (uint16_t)(desc_to_clean_to -
> nb_tx_desc);
> 
>  	desc_to_clean_to = sw_ring[desc_to_clean_to].last_id;
> -	if (!(txd[desc_to_clean_to].cmd_type_offset_bsz &
> -		rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE))) {
> +	if ((txd[desc_to_clean_to].cmd_type_offset_bsz &
> +
> 	rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) !=
> +
> 	rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE)) {
>  		PMD_TX_FREE_LOG(DEBUG, "TX descriptor %4u is not done
> "
>  			"(port=%d queue=%d)", desc_to_clean_to,
>  				txq->port_id, txq->queue_id);
> @@ -1431,8 +1432,9 @@ i40e_tx_free_bufs(struct i40e_tx_queue *txq)
>  	struct i40e_tx_entry *txep;
>  	uint16_t i;
> 
> -	if (!(txq->tx_ring[txq->tx_next_dd].cmd_type_offset_bsz &
> -
> 	rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE)))
> +	if ((txq->tx_ring[txq->tx_next_dd].cmd_type_offset_bsz &
> +
> 	rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) !=
> +
> 	rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE))
>  		return 0;
> 
>  	txep = &(txq->sw_ring[txq->tx_next_dd - (txq->tx_rs_thresh - 1)]);
> --
> 1.8.4.2