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>
This commit is contained in:
Ralph Campbell 2007-12-14 19:22:34 -08:00 committed by Roland Dreier
parent e57d62a147
commit cc65edcf0c
2 changed files with 12 additions and 12 deletions

View File

@ -647,6 +647,7 @@ static void send_rc_ack(struct ipath_qp *qp)
queue_ack: queue_ack:
spin_lock_irqsave(&qp->s_lock, flags); spin_lock_irqsave(&qp->s_lock, flags);
dev->n_rc_qacks++;
qp->s_flags |= IPATH_S_ACK_PENDING; qp->s_flags |= IPATH_S_ACK_PENDING;
qp->s_nak_state = qp->r_nak_state; qp->s_nak_state = qp->r_nak_state;
qp->s_ack_psn = qp->r_ack_psn; qp->s_ack_psn = qp->r_ack_psn;
@ -798,11 +799,13 @@ bail:
static inline void update_last_psn(struct ipath_qp *qp, u32 psn) static inline void update_last_psn(struct ipath_qp *qp, u32 psn)
{ {
if (qp->s_wait_credit) { if (qp->s_last_psn != psn) {
qp->s_wait_credit = 0; qp->s_last_psn = psn;
tasklet_hi_schedule(&qp->s_task); 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 @@ void ipath_rc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
case OP(SEND_FIRST): case OP(SEND_FIRST):
if (!ipath_get_rwqe(qp, 0)) { if (!ipath_get_rwqe(qp, 0)) {
rnr_nak: 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_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
qp->r_ack_psn = qp->r_psn; qp->r_ack_psn = qp->r_psn;
goto send_ack; goto send_ack;

View File

@ -98,11 +98,15 @@ void ipath_insert_rnr_queue(struct ipath_qp *qp)
while (qp->s_rnr_timeout >= nqp->s_rnr_timeout) { while (qp->s_rnr_timeout >= nqp->s_rnr_timeout) {
qp->s_rnr_timeout -= nqp->s_rnr_timeout; qp->s_rnr_timeout -= nqp->s_rnr_timeout;
l = l->next; l = l->next;
if (l->next == &dev->rnrwait) if (l->next == &dev->rnrwait) {
nqp = NULL;
break; break;
}
nqp = list_entry(l->next, struct ipath_qp, nqp = list_entry(l->next, struct ipath_qp,
timerwait); timerwait);
} }
if (nqp)
nqp->s_rnr_timeout -= qp->s_rnr_timeout;
list_add(&qp->timerwait, l); list_add(&qp->timerwait, l);
} }
spin_unlock_irqrestore(&dev->pending_lock, flags); spin_unlock_irqrestore(&dev->pending_lock, flags);