2 files changed, 14 insertions, 0 deletions

diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
index c1a70985abfa..af867731a5f4 100644
--- a/drivers/s390/cio/qdio.h
+++ b/drivers/s390/cio/qdio.h
@@ -16,6 +16,14 @@
 #define QDIO_BUSY_BIT_GIVE_UP           2000000 /* 2 seconds = eternity */
 #define QDIO_INPUT_THRESHOLD            500     /* 500 microseconds */
 
+/*
+ * if an asynchronous HiperSockets queue runs full, the 10 seconds timer wait
+ * till next initiative to give transmitted skbs back to the stack is too long.
+ * Therefore polling is started in case of multicast queue is filled more
+ * than 50 percent.
+ */
+#define QDIO_IQDIO_POLL_LVL             65      /* HS multicast queue */
+
 enum qdio_irq_states {
         QDIO_IRQ_STATE_INACTIVE,
         QDIO_IRQ_STATE_ESTABLISHED,
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index e6eabc853422..9307512132fe 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -851,6 +851,12 @@ static void __qdio_outbound_processing(struct qdio_q *q)
         if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q))
                 return;
 
+        if ((queue_type(q) == QDIO_IQDIO_QFMT) &&
+            (atomic_read(&q->nr_buf_used)) > QDIO_IQDIO_POLL_LVL) {
+                tasklet_schedule(&q->tasklet);
+                return;
+        }
+
         if (q->u.out.pci_out_enabled)
                 return;