Date: Fri, 1 Apr 2011 20:24:51 +0000 (UTC) From: Jack F Vogel <jfv@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r220254 - head/sys/dev/e1000 Message-ID: <201104012024.p31KOpvX058131@svn.freebsd.org>
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Author: jfv Date: Fri Apr 1 20:24:51 2011 New Revision: 220254 URL: http://svn.freebsd.org/changeset/base/220254 Log: Fix to an error condition case, when an mbuf chain get's defragged due to a mapping failure the header pointers will be invalidated and can result in a TSO or other failure down the line. So, when the remapping occurs force a retry thru the offload calculation code. Thanks to Andrew Boyer for discovering this and cooking up the fix!! Modified: head/sys/dev/e1000/if_em.c Modified: head/sys/dev/e1000/if_em.c ============================================================================== --- head/sys/dev/e1000/if_em.c Fri Apr 1 19:57:27 2011 (r220253) +++ head/sys/dev/e1000/if_em.c Fri Apr 1 20:24:51 2011 (r220254) @@ -1761,8 +1761,9 @@ em_xmit(struct tx_ring *txr, struct mbuf u32 txd_upper, txd_lower, txd_used, txd_saved; int ip_off, poff; int nsegs, i, j, first, last = 0; - int error, do_tso, tso_desc = 0; + int error, do_tso, tso_desc = 0, remap = 1; +retry: m_head = *m_headp; txd_upper = txd_lower = txd_used = txd_saved = 0; do_tso = ((m_head->m_pkthdr.csum_flags & CSUM_TSO) != 0); @@ -1900,7 +1901,7 @@ em_xmit(struct tx_ring *txr, struct mbuf * All other errors, in particular EINVAL, are fatal and prevent the * mbuf chain from ever going through. Drop it and report error. */ - if (error == EFBIG) { + if (error == EFBIG && remap) { struct mbuf *m; m = m_defrag(*m_headp, M_DONTWAIT); @@ -1912,20 +1913,9 @@ em_xmit(struct tx_ring *txr, struct mbuf } *m_headp = m; - /* Try it again */ - error = bus_dmamap_load_mbuf_sg(txr->txtag, map, - *m_headp, segs, &nsegs, BUS_DMA_NOWAIT); - - if (error == ENOMEM) { - adapter->no_tx_dma_setup++; - return (error); - } else if (error != 0) { - adapter->no_tx_dma_setup++; - m_freem(*m_headp); - *m_headp = NULL; - return (error); - } - + /* Try it again, but only once */ + remap = 0; + goto retry; } else if (error == ENOMEM) { adapter->no_tx_dma_setup++; return (error);
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