lkml.org 
[lkml]   [2007]   [Mar]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH 10 of 33] IB/ipath - fix PSN update for RC retries
Date
From
# HG changeset patch
# User Ralph Campbell <ralph.campbell@qlogic.com>
# Date 1173994464 25200
# Node ID 4050989280f08d81d06642e3d6cf5c3ea4397107
# Parent ec38d8f91d79a765cf53aaa7e8a59622418f2c9f
IB/ipath - fix PSN update for RC retries

This patch fixes a number of bugs with updating the PSN for retries of
RC requests.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>

diff -r ec38d8f91d79 -r 4050989280f0 drivers/infiniband/hw/ipath/ipath_rc.c
--- a/drivers/infiniband/hw/ipath/ipath_rc.c Thu Mar 15 14:34:24 2007 -0700
+++ b/drivers/infiniband/hw/ipath/ipath_rc.c Thu Mar 15 14:34:24 2007 -0700
@@ -444,7 +444,7 @@ int ipath_make_rc_req(struct ipath_qp *q
qp->s_psn = wqe->lpsn + 1;
else {
qp->s_psn++;
- if ((int)(qp->s_psn - qp->s_next_psn) > 0)
+ if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
}
/*
@@ -471,7 +471,7 @@ int ipath_make_rc_req(struct ipath_qp *q
/* FALLTHROUGH */
case OP(SEND_MIDDLE):
bth2 = qp->s_psn++ & IPATH_PSN_MASK;
- if ((int)(qp->s_psn - qp->s_next_psn) > 0)
+ if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
ss = &qp->s_sge;
len = qp->s_len;
@@ -507,7 +507,7 @@ int ipath_make_rc_req(struct ipath_qp *q
/* FALLTHROUGH */
case OP(RDMA_WRITE_MIDDLE):
bth2 = qp->s_psn++ & IPATH_PSN_MASK;
- if ((int)(qp->s_psn - qp->s_next_psn) > 0)
+ if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
ss = &qp->s_sge;
len = qp->s_len;
@@ -546,7 +546,7 @@ int ipath_make_rc_req(struct ipath_qp *q
qp->s_state = OP(RDMA_READ_REQUEST);
hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
bth2 = qp->s_psn++ & IPATH_PSN_MASK;
- if ((int)(qp->s_psn - qp->s_next_psn) > 0)
+ if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
ss = NULL;
len = 0;
@@ -779,7 +779,7 @@ void ipath_restart_rc(struct ipath_qp *q
if (wqe->wr.opcode == IB_WR_RDMA_READ)
dev->n_rc_resends++;
else
- dev->n_rc_resends += (int)qp->s_psn - (int)psn;
+ dev->n_rc_resends += (qp->s_psn - psn) & IPATH_PSN_MASK;

reset_psn(qp, psn);
tasklet_hi_schedule(&qp->s_task);
@@ -915,15 +915,19 @@ static int do_rc_ack(struct ipath_qp *qp
if (qp->s_last == qp->s_cur) {
if (++qp->s_cur >= qp->s_size)
qp->s_cur = 0;
+ qp->s_last = qp->s_cur;
+ if (qp->s_last == qp->s_tail)
+ break;
wqe = get_swqe_ptr(qp, qp->s_cur);
qp->s_state = OP(SEND_LAST);
qp->s_psn = wqe->psn;
- }
- if (++qp->s_last >= qp->s_size)
- qp->s_last = 0;
- wqe = get_swqe_ptr(qp, qp->s_last);
- if (qp->s_last == qp->s_tail)
- break;
+ } else {
+ if (++qp->s_last >= qp->s_size)
+ qp->s_last = 0;
+ if (qp->s_last == qp->s_tail)
+ break;
+ wqe = get_swqe_ptr(qp, qp->s_last);
+ }
}

switch (aeth >> 29) {
@@ -935,6 +939,18 @@ static int do_rc_ack(struct ipath_qp *qp
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,
+ * we can stop resending the earlier packets and
+ * continue with the next packet the receiver wants.
+ */
+ if (ipath_cmp24(qp->s_psn, psn) <= 0) {
+ reset_psn(qp, psn + 1);
+ tasklet_hi_schedule(&qp->s_task);
+ }
+ } else if (ipath_cmp24(qp->s_psn, psn) <= 0) {
+ qp->s_state = OP(SEND_LAST);
+ qp->s_psn = psn + 1;
}
ipath_get_credit(qp, aeth);
qp->s_rnr_retry = qp->s_rnr_retry_cnt;
@@ -945,22 +961,23 @@ static int do_rc_ack(struct ipath_qp *qp

case 1: /* RNR NAK */
dev->n_rnr_naks++;
+ if (qp->s_last == qp->s_tail)
+ goto bail;
if (qp->s_rnr_retry == 0) {
- if (qp->s_last == qp->s_tail)
- goto bail;
-
wc.status = IB_WC_RNR_RETRY_EXC_ERR;
goto class_b;
}
if (qp->s_rnr_retry_cnt < 7)
qp->s_rnr_retry--;
- if (qp->s_last == qp->s_tail)
- goto bail;

/* The last valid PSN is the previous PSN. */
update_last_psn(qp, psn - 1);

- dev->n_rc_resends += (int)qp->s_psn - (int)psn;
+ if (wqe->wr.opcode == IB_WR_RDMA_READ)
+ dev->n_rc_resends++;
+ else
+ dev->n_rc_resends +=
+ (qp->s_psn - psn) & IPATH_PSN_MASK;

reset_psn(qp, psn);

@@ -971,26 +988,20 @@ static int do_rc_ack(struct ipath_qp *qp
goto bail;

case 3: /* NAK */
- /* The last valid PSN seen is the previous request's. */
- if (qp->s_last != qp->s_tail)
- update_last_psn(qp, wqe->psn - 1);
+ if (qp->s_last == qp->s_tail)
+ goto bail;
+ /* The last valid PSN is the previous PSN. */
+ update_last_psn(qp, psn - 1);
switch ((aeth >> IPATH_AETH_CREDIT_SHIFT) &
IPATH_AETH_CREDIT_MASK) {
case 0: /* PSN sequence error */
dev->n_seq_naks++;
/*
- * Back up to the responder's expected PSN. XXX
+ * Back up to the responder's expected PSN.
* Note that we might get a NAK in the middle of an
* RDMA READ response which terminates the RDMA
* READ.
*/
- if (qp->s_last == qp->s_tail)
- break;
-
- if (ipath_cmp24(psn, wqe->psn) < 0)
- break;
-
- /* Retry the request. */
ipath_restart_rc(qp, psn, &wc);
break;

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-03-15 23:27    [W:0.195 / U:6.056 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site