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>

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;

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 @@ int qeth_send_control_data(struct qeth_card *card, int len,
 	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 @@ int qeth_core_hardsetup_card(struct qeth_card *card)
 		else
 			goto retry;
 	}
+	card->read_or_write_problem = 0;
 	rc = qeth_mpc_initialize(card);
 	if (rc) {
 		QETH_DBF_TEXT_(SETUP, 2, "5err%d", rc);