> -----Original Message-----
> From: Sexton, Rory
> Sent: Thursday, January 19, 2017 6:38 PM
> To: Wu, Jingjing <jingjing...@intel.com>
> Cc: dev@dpdk.org; Marjanovic, Nemanja <nemanja.marjano...@intel.com>
> Subject: RE: [PATCH v2] net/i40e: set no drop for traffic class
>
> Perhaps the best solution is as suggested to set
> rte_eth_conf.dcb_capability_en
> = ETH_DCB_PFC_SUPPORT rte_eth_conf.rxmode.mq_mode =
> ETH_MQ_RX_DCB_FLAG and set rte_eth_dcb_rx_conf.nb_tcs to the number of
> tc's to apply Using this port configuration will give the same behavior of the
> patch and it removes the need for an API change.
>
> Rory
>
Yes, That's what I thought when the v1 patch. So do we still need this patch
now?
> -----Original Message-----
> From: Wu, Jingjing
> Sent: Tuesday, January 17, 2017 3:09 PM
> To: Sexton, Rory <rory.sex...@intel.com>
> Cc: dev@dpdk.org; Marjanovic, Nemanja <nemanja.marjano...@intel.com>
> Subject: RE: [PATCH v2] net/i40e: set no drop for traffic class
>
>
>
> > -----Original Message-----
> > From: Sexton, Rory
> > Sent: Monday, January 16, 2017 11:52 PM
> > To: Wu, Jingjing <jingjing...@intel.com>
> > Cc: dev@dpdk.org; Sexton, Rory <rory.sex...@intel.com>; Marjanovic,
> > Nemanja <nemanja.marjano...@intel.com>
> > Subject: [PATCH v2] net/i40e: set no drop for traffic class
> >
> > From: Rory Sexton <rory.sex...@intel.com>
> >
> > The default traffic class in i40e is set to drop versus on ixgbe it
> > isset to no drop. This means when packets build up in the RX SRAM on
> > the NIC, they are dropped, and they do this when the SW descriptor rings
> > fill up.
> >
> > This patch changes this behaviour and our testing shows there are no
> > drops as a result.
> >
> > Signed-off-by: Rory Sexton <rory.sex...@intel.com>
> > Signed-off-by: Nemanja Marjanovic <nemanja.marjano...@intel.com>
> > ---
> > v2:
> > * Changed to use existing api to set priority register directly.
> >
> > drivers/net/i40e/i40e_ethdev.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/net/i40e/i40e_ethdev.c
> > b/drivers/net/i40e/i40e_ethdev.c index 67778ba..97339b5 100644
> > --- a/drivers/net/i40e/i40e_ethdev.c
> > +++ b/drivers/net/i40e/i40e_ethdev.c
> > @@ -2985,8 +2985,11 @@ static int
> > i40e_priority_flow_ctrl_set(__rte_unused struct rte_eth_dev *dev,
> > __rte_unused struct rte_eth_pfc_conf *pfc_conf) {
> > + struct i40e_hw *hw = I40E_DEV_PRIVATE_TO_HW(dev->data-
> > >dev_private);
> > +
> > PMD_INIT_FUNC_TRACE();
> >
> > + I40E_WRITE_REG(hw, I40E_PRTDCB_TC2PFC, 0xff);
>
> PRTDCB_TC2PFC is the Bitmap who controls the use of Priority Flow Control
> (PFC) per each TC. Bit n set to 1b indicates TC n uses PFC in Rx and Tx. The
> TC is
> referred as a no-drop TC.
>
> And if look the rte_eth_pfc_conf, there is a field called priority, which
> would
> map to a TC.
> Currently, the TC and priority is 1:1 map when dcb is enabled.
> So how about change it like:
> Check dcb info, and map the priority to tc, then val = 0x1 << tc;
> I40E_WRITE_REG(hw, I40E_PRTDCB_TC2PFC, val);
>
> Thanks
> Jingjing
>
>
>
> > return -ENOSYS;
> > }
> >
> > --
> > 2.4.3
