IB/ipath: simplify IB timer usage

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 12 insertions, 30 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_verbs.c b/drivers/infiniband/hw/ipath/ipath_verbs.c
index 8d2558a01f35..cb9e387c301f 100644
--- a/drivers/infiniband/hw/ipath/ipath_verbs.c
+++ b/drivers/infiniband/hw/ipath/ipath_verbs.c
@@ -449,7 +449,6 @@ static void ipath_ib_timer(void *arg)
 {
         struct ipath_ibdev *dev = (struct ipath_ibdev *) arg;
         struct ipath_qp *resend = NULL;
-        struct ipath_qp *rnr = NULL;
         struct list_head *last;
         struct ipath_qp *qp;
         unsigned long flags;
@@ -465,32 +464,18 @@ static void ipath_ib_timer(void *arg)
         last = &dev->pending[dev->pending_index];
         while (!list_empty(last)) {
                 qp = list_entry(last->next, struct ipath_qp, timerwait);
-                if (last->next == LIST_POISON1 ||
-                    last->next != &qp->timerwait ||
-                    qp->timerwait.prev != last) {
-                        INIT_LIST_HEAD(last);
-                } else {
-                        list_del(&qp->timerwait);
-                        qp->timerwait.prev = (struct list_head *) resend;
-                        resend = qp;
-                        atomic_inc(&qp->refcount);
-                }
+                list_del(&qp->timerwait);
+                qp->timer_next = resend;
+                resend = qp;
+                atomic_inc(&qp->refcount);
         }
         last = &dev->rnrwait;
         if (!list_empty(last)) {
                 qp = list_entry(last->next, struct ipath_qp, timerwait);
                 if (--qp->s_rnr_timeout == 0) {
                         do {
-                                if (last->next == LIST_POISON1 ||
-                                    last->next != &qp->timerwait ||
-                                    qp->timerwait.prev != last) {
-                                        INIT_LIST_HEAD(last);
-                                        break;
-                                }
                                 list_del(&qp->timerwait);
-                                qp->timerwait.prev =
-                                        (struct list_head *) rnr;
-                                rnr = qp;
+                                tasklet_hi_schedule(&qp->s_task);
                                 if (list_empty(last))
                                         break;
                                 qp = list_entry(last->next, struct ipath_qp,
@@ -530,8 +515,7 @@ static void ipath_ib_timer(void *arg)
         spin_unlock_irqrestore(&dev->pending_lock, flags);
 
         /* XXX What if timer fires again while this is running? */
-        for (qp = resend; qp != NULL;
-             qp = (struct ipath_qp *) qp->timerwait.prev) {
+        for (qp = resend; qp != NULL; qp = qp->timer_next) {
                 struct ib_wc wc;
 
                 spin_lock_irqsave(&qp->s_lock, flags);
@@ -545,9 +529,6 @@ static void ipath_ib_timer(void *arg)
                 if (atomic_dec_and_test(&qp->refcount))
                         wake_up(&qp->wait);
         }
-        for (qp = rnr; qp != NULL;
-             qp = (struct ipath_qp *) qp->timerwait.prev)
-                tasklet_hi_schedule(&qp->s_task);
 }
 
 /**
@@ -556,9 +537,9 @@ static void ipath_ib_timer(void *arg)
  *
  * This is called from ipath_intr() at interrupt level when a PIO buffer is
  * available after ipath_verbs_send() returned an error that no buffers were
- * available.  Return 0 if we consumed all the PIO buffers and we still have
+ * available.  Return 1 if we consumed all the PIO buffers and we still have
  * QPs waiting for buffers (for now, just do a tasklet_hi_schedule and
- * return one).
+ * return zero).
  */
 static int ipath_ib_piobufavail(void *arg)
 {
@@ -579,7 +560,7 @@ static int ipath_ib_piobufavail(void *arg)
         spin_unlock_irqrestore(&dev->pending_lock, flags);
 
 bail:
-        return 1;
+        return 0;
 }
 
 static int ipath_query_device(struct ib_device *ibdev,
@@ -1159,7 +1140,7 @@ static ssize_t show_stats(struct class_device *cdev, char *buf)
 
         len = sprintf(buf,
                       "RC resends  %d\n"
-                      "RC QACKs    %d\n"
+                      "RC no QACK  %d\n"
                       "RC ACKs     %d\n"
                       "RC SEQ NAKs %d\n"
                       "RC RDMA seq %d\n"
diff --git a/drivers/infiniband/hw/ipath/ipath_verbs.h b/drivers/infiniband/hw/ipath/ipath_verbs.h
index fcafbc7c9e71..4f8d59300e9b 100644
--- a/drivers/infiniband/hw/ipath/ipath_verbs.h
+++ b/drivers/infiniband/hw/ipath/ipath_verbs.h
@@ -282,7 +282,8 @@ struct ipath_srq {
  */
 struct ipath_qp {
         struct ib_qp ibqp;
-        struct ipath_qp *next;  /* link list for QPN hash table */
+        struct ipath_qp *next;          /* link list for QPN hash table */
+        struct ipath_qp *timer_next;    /* link list for ipath_ib_timer() */
         struct list_head piowait;       /* link for wait PIO buf */
         struct list_head timerwait;     /* link for waiting for timeouts */
         struct ib_ah_attr remote_ah_attr;