IB/qib: Fix interrupt mitigation

For SusieQ we need to write to the interrupt timer register before
updating the header queue head with interrupt count.  This is to
ensure that the timer is enabled properly and a receive available
interrupt is delivered.  Otherwise this interrupt can be lost if the
receiver header/eager queues are full before the timer is enabled.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/infiniband/hw/qib/qib_iba7322.c b/drivers/infiniband/hw/qib/qib_iba7322.c
index a9c8c7235fcd..9bc6d0835e30 100644
--- a/drivers/infiniband/hw/qib/qib_iba7322.c
+++ b/drivers/infiniband/hw/qib/qib_iba7322.c
@@ -2823,7 +2823,6 @@ static irqreturn_t qib_7322intr(int irq, void *data)
                                 ctxtrbits &= ~rmask;
                                 if (dd->rcd[i]) {
                                         qib_kreceive(dd->rcd[i], NULL, &npkts);
-                                        adjust_rcv_timeout(dd->rcd[i], npkts);
                                 }
                         }
                         rmask <<= 1;
@@ -2873,7 +2872,6 @@ static irqreturn_t qib_7322pintr(int irq, void *data)
                        (1ULL << QIB_I_RCVURG_LSB)) << rcd->ctxt);
 
         qib_kreceive(rcd, NULL, &npkts);
-        adjust_rcv_timeout(rcd, npkts);
 
         return IRQ_HANDLED;
 }
@@ -4047,8 +4045,14 @@ static int qib_7322_set_ib_table(struct qib_pportdata *ppd, int which, void *t)
 }
 
 static void qib_update_7322_usrhead(struct qib_ctxtdata *rcd, u64 hd,
-                                    u32 updegr, u32 egrhd)
+                                    u32 updegr, u32 egrhd, u32 npkts)
 {
+        /*
+         * Need to write timeout register before updating rcvhdrhead to ensure
+         * that the timer is enabled on reception of a packet.
+         */
+        if (hd >> IBA7322_HDRHEAD_PKTINT_SHIFT)
+                adjust_rcv_timeout(rcd, npkts);
         qib_write_ureg(rcd->dd, ur_rcvhdrhead, hd, rcd->ctxt);
         qib_write_ureg(rcd->dd, ur_rcvhdrhead, hd, rcd->ctxt);
         if (updegr)