From: Ralph Campbell Date: Fri, 26 Oct 2007 15:02:39 +0000 (-0700) Subject: IB/ipath: Fix race with ACK retry timeout list management X-Git-Tag: v2.6.24-rc3~14^2~4 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=f4ad1bcc4425a772ea584e1f24abadc64c2b839f;p=linux-2.6-omap-h63xx.git IB/ipath: Fix race with ACK retry timeout list management When an ACK is received, the QP is removed from the timeout list and then if there are still pending send WQEs, the QP is put back on the timeout list. It is possible that another post send has put the QP on the timeout list thus, a check needs to be made before trying to do it again or the list is corrupted. Signed-off-by: Ralph Campbell Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/hw/ipath/ipath_rc.c b/drivers/infiniband/hw/ipath/ipath_rc.c index 5c29b2bfea1..120a61b03bc 100644 --- a/drivers/infiniband/hw/ipath/ipath_rc.c +++ b/drivers/infiniband/hw/ipath/ipath_rc.c @@ -959,8 +959,9 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode, /* If this is a partial ACK, reset the retransmit timer. */ if (qp->s_last != qp->s_tail) { spin_lock(&dev->pending_lock); - list_add_tail(&qp->timerwait, - &dev->pending[dev->pending_index]); + if (list_empty(&qp->timerwait)) + list_add_tail(&qp->timerwait, + &dev->pending[dev->pending_index]); spin_unlock(&dev->pending_lock); /* * If we get a partial ACK for a resent operation,