From 5995ee9a987472a09da2186b9ef8efe23d83907d Mon Sep 17 00:00:00 2001 From: adrian Date: Sat, 11 Oct 2014 22:12:24 +0000 Subject: MFC r271645 - Set DROP_EN on each RX queue if transmit flow-control is disabled. This allows the NIC to drop frames on the receive queue and not cause the MAC to block on receiving to _any_ queue. Tested: igb0@pci0:5:0:0: class=0x020000 card=0x152115d9 chip=0x15218086 rev=0x01 hdr=0x00 vendor = 'Intel Corporation' device = 'I350 Gigabit Network Connection' class = network subclass = ethernet Discussed with: Eric Joyner MFC after: 1 week Sponsored by: Norse Corp, Inc. --- sys/dev/e1000/if_igb.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/sys/dev/e1000/if_igb.c b/sys/dev/e1000/if_igb.c index 484cba1..b1fc572 100644 --- a/sys/dev/e1000/if_igb.c +++ b/sys/dev/e1000/if_igb.c @@ -4517,6 +4517,18 @@ igb_initialize_receive_units(struct adapter *adapter) rctl |= E1000_RCTL_SZ_2048; } + /* + * If TX flow control is disabled and there's >1 queue defined, + * enable DROP. + * + * This drops frames rather than hanging the RX MAC for all queues. + */ + if ((adapter->num_queues > 1) && + (adapter->fc == e1000_fc_none || + adapter->fc == e1000_fc_rx_pause)) { + srrctl |= E1000_SRRCTL_DROP_EN; + } + /* Setup the Base and Length of the Rx Descriptor Rings */ for (int i = 0; i < adapter->num_queues; i++, rxr++) { u64 bus_addr = rxr->rxdma.dma_paddr; @@ -6053,6 +6065,7 @@ igb_set_flowcntl(SYSCTL_HANDLER_ARGS) adapter->hw.fc.current_mode = adapter->hw.fc.requested_mode; e1000_force_mac_fc(&adapter->hw); + /* XXX TODO: update DROP_EN on each RX queue if appropriate */ return (error); } -- cgit v1.1