s390/qeth: don't fake a TX completion interrupt after TX error

When do_qdio() returns with an unexpected error, qeth_flush_buffers()
kicks off a recovery action.

In such a case there's no point in starting TX completion processing,
the device gets torn down anyway. So take a closer look at do_qdio()'s
return value, and skip the TX completion processing accordingly.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index de9d27e1c529062596c4e57a6a843911699cfb1e..ea2e139cd592d59612909fa797ff5a1480273554 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -3692,24 +3692,27 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index,
        rc = do_QDIO(CARD_DDEV(queue->card), qdio_flags,
                     queue->queue_no, index, count);
 
-       /* Fake the TX completion interrupt: */
-       if (IS_IQD(card)) {
-               unsigned int frames = READ_ONCE(queue->max_coalesced_frames);
-               unsigned int usecs = READ_ONCE(queue->coalesce_usecs);
+       switch (rc) {
+       case 0:
+       case -ENOBUFS:
+               /* ignore temporary SIGA errors without busy condition */
 
-               if (frames && queue->coalesced_frames >= frames) {
-                       napi_schedule(&queue->napi);
-                       queue->coalesced_frames = 0;
-                       QETH_TXQ_STAT_INC(queue, coal_frames);
-               } else if (usecs) {
-                       qeth_tx_arm_timer(queue, usecs);
+               /* Fake the TX completion interrupt: */
+               if (IS_IQD(card)) {
+                       unsigned int frames = READ_ONCE(queue->max_coalesced_frames);
+                       unsigned int usecs = READ_ONCE(queue->coalesce_usecs);
+
+                       if (frames && queue->coalesced_frames >= frames) {
+                               napi_schedule(&queue->napi);
+                               queue->coalesced_frames = 0;
+                               QETH_TXQ_STAT_INC(queue, coal_frames);
+                       } else if (usecs) {
+                               qeth_tx_arm_timer(queue, usecs);
+                       }
                }
-       }
 
-       if (rc) {
-               /* ignore temporary SIGA errors without busy condition */
-               if (rc == -ENOBUFS)
-                       return;
+               break;
+       default:
                QETH_CARD_TEXT(queue->card, 2, "flushbuf");
                QETH_CARD_TEXT_(queue->card, 2, " q%d", queue->queue_no);
                QETH_CARD_TEXT_(queue->card, 2, " idx%d", index);
@@ -3719,7 +3722,6 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index,
                /* this must not happen under normal circumstances. if it
                 * happens something is really wrong -> recover */
                qeth_schedule_recovery(queue->card);
-               return;
        }
 }