IB/ipath: Fix RNR NAK handling
This patch fixes a couple of minor problems with RNR NAK handling:
- The insertion sort was causing extra delay when inserting ahead
vs. behind an existing entry on the list.
- A resend of a first packet of a message which is still not ready,
needs another RNR NAK (i.e., it was suppressed when it shouldn't).
- Also, the resend tasklet doesn't need to be woken up unless the
ACK/NAK actually indicates progress has been made.
Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/ipath/ipath_rc.c b/drivers/infiniband/hw/ipath/ipath_rc.c
index 120a61b..459e46e 100644
--- a/drivers/infiniband/hw/ipath/ipath_rc.c
+++ b/drivers/infiniband/hw/ipath/ipath_rc.c
@@ -647,6 +647,7 @@
queue_ack:
spin_lock_irqsave(&qp->s_lock, flags);
+ dev->n_rc_qacks++;
qp->s_flags |= IPATH_S_ACK_PENDING;
qp->s_nak_state = qp->r_nak_state;
qp->s_ack_psn = qp->r_ack_psn;
@@ -798,11 +799,13 @@
static inline void update_last_psn(struct ipath_qp *qp, u32 psn)
{
- if (qp->s_wait_credit) {
- qp->s_wait_credit = 0;
- tasklet_hi_schedule(&qp->s_task);
+ if (qp->s_last_psn != psn) {
+ qp->s_last_psn = psn;
+ if (qp->s_wait_credit) {
+ qp->s_wait_credit = 0;
+ tasklet_hi_schedule(&qp->s_task);
+ }
}
- qp->s_last_psn = psn;
}
/**
@@ -1653,13 +1656,6 @@
case OP(SEND_FIRST):
if (!ipath_get_rwqe(qp, 0)) {
rnr_nak:
- /*
- * A RNR NAK will ACK earlier sends and RDMA writes.
- * Don't queue the NAK if a RDMA read or atomic
- * is pending though.
- */
- if (qp->r_nak_state)
- goto done;
qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
qp->r_ack_psn = qp->r_psn;
goto send_ack;
diff --git a/drivers/infiniband/hw/ipath/ipath_ruc.c b/drivers/infiniband/hw/ipath/ipath_ruc.c
index 1b4f7e1..a59bdbd 100644
--- a/drivers/infiniband/hw/ipath/ipath_ruc.c
+++ b/drivers/infiniband/hw/ipath/ipath_ruc.c
@@ -98,11 +98,15 @@
while (qp->s_rnr_timeout >= nqp->s_rnr_timeout) {
qp->s_rnr_timeout -= nqp->s_rnr_timeout;
l = l->next;
- if (l->next == &dev->rnrwait)
+ if (l->next == &dev->rnrwait) {
+ nqp = NULL;
break;
+ }
nqp = list_entry(l->next, struct ipath_qp,
timerwait);
}
+ if (nqp)
+ nqp->s_rnr_timeout -= qp->s_rnr_timeout;
list_add(&qp->timerwait, l);
}
spin_unlock_irqrestore(&dev->pending_lock, flags);