Date: Mon, 15 Sep 2014 19:53:49 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r271645 - head/sys/dev/e1000 Message-ID: <201409151953.s8FJrnAJ075730@svn.freebsd.org>
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Author: adrian Date: Mon Sep 15 19:53:49 2014 New Revision: 271645 URL: http://svnweb.freebsd.org/changeset/base/271645 Log: 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 <eric.joyner@intel.com> MFC after: 1 week Sponsored by: Norse Corp, Inc. Modified: head/sys/dev/e1000/if_igb.c Modified: head/sys/dev/e1000/if_igb.c ============================================================================== --- head/sys/dev/e1000/if_igb.c Mon Sep 15 19:48:27 2014 (r271644) +++ head/sys/dev/e1000/if_igb.c Mon Sep 15 19:53:49 2014 (r271645) @@ -4712,6 +4712,18 @@ igb_initialize_receive_units(struct adap 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; @@ -6255,6 +6267,7 @@ 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); }
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