Re: [PATCH v2] net/i40e: set no drop for traffic class
From: Wu, Jingjing <hidden>
Date: 2017-01-17 15:09:21
quoted hunk ↗ jump to hunk
-----Original Message----- From: Sexton, Rory Sent: Monday, January 16, 2017 11:52 PM To: Wu, Jingjing <redacted> Cc: dev@dpdk.org; Sexton, Rory <redacted>; Marjanovic, Nemanja [off-list ref] Subject: [PATCH v2] net/i40e: set no drop for traffic class From: Rory Sexton <redacted> 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 <redacted> Signed-off-by: Nemanja Marjanovic <redacted> --- 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-quoted
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