qeth: avoid loop if ipa command response is missing

If qeth issues an ipa command, but for some reasons the response
never comes back, qeth reaches a timeout.
Reset the irq_pending flag of the write channel in timeout handling
code and trigger a recovery to avoid endless looping for the following
ipa command.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 0 deletions

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 41ddf86c342..d1257768be9 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -740,6 +740,7 @@ struct qeth_card {
         struct qeth_qdio_info qdio;
         struct qeth_perf_stats perf_stats;
         int use_hard_stop;
+        int read_or_write_problem;
         struct qeth_osn_info osn_info;
         struct qeth_discipline discipline;
         atomic_t force_alloc_skb;
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index f33da45c35e..7f3ea77551e 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -262,6 +262,7 @@ static int qeth_issue_next_read(struct qeth_card *card)
                 QETH_DBF_MESSAGE(2, "%s error in starting next read ccw! "
                         "rc=%i\n", dev_name(&card->gdev->dev), rc);
                 atomic_set(&card->read.irq_pending, 0);
+                card->read_or_write_problem = 1;
                 qeth_schedule_recovery(card);
                 wake_up(&card->wait_q);
         }
@@ -382,6 +383,7 @@ void qeth_clear_ipacmd_list(struct qeth_card *card)
                 qeth_put_reply(reply);
         }
         spin_unlock_irqrestore(&card->lock, flags);
+        atomic_set(&card->write.irq_pending, 0);
 }
 EXPORT_SYMBOL_GPL(qeth_clear_ipacmd_list);
 
@@ -1076,6 +1078,7 @@ static int qeth_setup_card(struct qeth_card *card)
         card->state = CARD_STATE_DOWN;
         card->lan_online = 0;
         card->use_hard_stop = 0;
+        card->read_or_write_problem = 0;
         card->dev = NULL;
         spin_lock_init(&card->vlanlock);
         spin_lock_init(&card->mclock);
@@ -1658,6 +1661,10 @@ int qeth_send_control_data(struct qeth_card *card, int len,
 
         QETH_CARD_TEXT(card, 2, "sendctl");
 
+        if (card->read_or_write_problem) {
+                qeth_release_buffer(iob->channel, iob);
+                return -EIO;
+        }
         reply = qeth_alloc_reply(card);
         if (!reply) {
                 return -ENOMEM;
@@ -1729,6 +1736,9 @@ time_err:
         spin_unlock_irqrestore(&reply->card->lock, flags);
         reply->rc = -ETIME;
         atomic_inc(&reply->received);
+        atomic_set(&card->write.irq_pending, 0);
+        qeth_release_buffer(iob->channel, iob);
+        card->write.buf_no = (card->write.buf_no + 1) % QETH_CMD_BUFFER_NO;
         wake_up(&reply->wait_q);
         rc = reply->rc;
         qeth_put_reply(reply);
@@ -2485,6 +2495,10 @@ int qeth_send_ipa_cmd(struct qeth_card *card, struct qeth_cmd_buffer *iob,
         qeth_prepare_ipa_cmd(card, iob, prot_type);
         rc = qeth_send_control_data(card, IPA_CMD_LENGTH,
                                                 iob, reply_cb, reply_param);
+        if (rc == -ETIME) {
+                qeth_clear_ipacmd_list(card);
+                qeth_schedule_recovery(card);
+        }
         return rc;
 }
 EXPORT_SYMBOL_GPL(qeth_send_ipa_cmd);
@@ -3967,6 +3981,7 @@ retriable:
                 else
                         goto retry;
         }
+        card->read_or_write_problem = 0;
         rc = qeth_mpc_initialize(card);
         if (rc) {
                 QETH_DBF_TEXT_(SETUP, 2, "5err%d", rc);