Commit:     683a2aa339f607c8a422835161ceab68b2a5a18a
Parent:     1a63e846a4099e6fbff86a3b112064378515f254
Author:     Herbert Xu <[EMAIL PROTECTED]>
AuthorDate: Sat Dec 16 12:04:33 2006 +1100
Committer:  Jeff Garzik <[EMAIL PROTECTED]>
CommitDate: Tue Dec 26 16:28:20 2006 -0500

    e1000: Do not truncate TSO TCP header with 82544 workaround
    The e1000 driver has a workaround for 82544 on PCI-X where if the
    terminating byte of a buffer is at addresses 0-3 mod 8, then 4 bytes
    are shaved off it and defered to a new segment.  This is due to an
    erratum that could otherwise cause TX hangs.
    Unfortunately this breaks TSO because it may cause the TCP header to
    be split over two segments which itself causes TX hangs.  The solution
    is to pull 4 bytes of data up from the next segment rather than pushing
    4 bytes off.  This ensures the TCP header remains in one piece and
    works around the PCI-X hang.
    This patch is based on one from Jesse Brandeburg.
    This bug has been trigered by both CONFIG_DEBUG_SLAB as well as Xen.
    Note that the only reason we don't see this normally is because the
    TCP stack starts writing from the end, i.e., it writes the TCP header
    first then slaps on the IP header, etc.  So the end of the TCP header
    (skb->tail - 1 here) is always aligned correctly.
    Had we made the start of the IP header (e.g., IPv6) 8-byte aligned
    instead, this would happen for normal TCP traffic as well.
    Signed-off-by: Herbert Xu <[EMAIL PROTECTED]>
    Acked-by: Jesse Brandeburg <[EMAIL PROTECTED]>
    Visit Openswan at
    Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]>
    Home Page:
    PGP Key:
    Signed-off-by: Jeff Garzik <[EMAIL PROTECTED]>
 drivers/net/e1000/e1000_main.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 8c4924f..4c1ff75 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -3318,6 +3318,16 @@ e1000_xmit_frame(struct sk_buff *skb, struct net_device 
                if (skb->data_len && (hdr_len == (skb->len - skb->data_len))) {
                        switch (adapter->hw.mac_type) {
                                unsigned int pull_size;
+                       case e1000_82544:
+                               /* Make sure we have room to chop off 4 bytes,
+                                * and that the end alignment will work out to
+                                * this hardware's requirements
+                                * NOTE: this is a TSO only workaround
+                                * if end byte alignment not correct move us
+                                * into the next dword */
+                               if ((unsigned long)(skb->tail - 1) & 4)
+                                       break;
+                               /* fall through */
                        case e1000_82571:
                        case e1000_82572:
                        case e1000_82573:
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