e1000: flush packets when link comes up
commit5df6a1855b62dc653515d919e48c5b6f00c48f32
authorStefan Hajnoczi <stefanha@redhat.com>
Thu, 25 Jun 2015 09:18:05 +0000 (25 10:18 +0100)
committerStefan Hajnoczi <stefanha@redhat.com>
Tue, 7 Jul 2015 12:10:26 +0000 (7 13:10 +0100)
treec59da9a485f47610aba2ca118ecc08f98658040d
parentec50dd4634ae06091e61f42b7ba975f9ed510ad0
e1000: flush packets when link comes up

e1000_can_receive() checks the link up status register bit.  If the bit
is clear, packets will be queued and the peer may disable receive to
avoid wasting CPU reading packets that cannot be delivered.  The queue
must be flushed once the link comes back up again.

This patch fixes broken e1000 receive with Mac OS X Snow Leopard guests
and tap networking.  Flushing the queue invokes the async send callback,
which re-enables tap fd read.

Reported-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1435223885-12745-1-git-send-email-stefanha@redhat.com
hw/net/e1000.c