Skip to contentSkip to conversation

FAILED: patch "[PATCH] s390/qeth: schedule TX NAPI on QAOB completion" failed to apply to 5.10-stable tree

PATCH [email protected] 1 participant 1 message Mar 12, 2021

Subsystems (4)
Network drivers Stable branch s390 s390 network drivers
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3e83d467a08e25b27c44c885f511624a71c84f7c Mon Sep 17 00:00:00 2001
From: Julian Wiedmann <[email protected]>
Date: Tue, 9 Mar 2021 17:52:20 +0100
Subject: [PATCH] s390/qeth: schedule TX NAPI on QAOB completion

When a QAOB notifies us that a pending TX buffer has been delivered, the actual TX completion processing by qeth_tx_complete_pending_bufs() is done within the context of a TX NAPI instance. We shouldn't rely on this instance being scheduled by some other TX event, but just do it ourselves.

qeth_qdio_handle_aob() is called from qeth_poll(), ie. our main NAPI instance. To avoid touching the TX queue's NAPI instance before/after it is (un-)registered, reorder the code in qeth_open() and qeth_stop() accordingly.

Fixes 0da9581ddb0f ("qeth: exploit asynchronous delivery of storage blocks")
Signed-off-by Julian Wiedmann <[email protected]>
Signed-off-by David S. Miller <[email protected]>
drivers/s390/net/qeth_core_main.c +12 -6
index 3763cd6d14f8..d0a56afec028 100644
@@ -470,6 +470,7 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
 	struct qaob *aob;
 	struct qeth_qdio_out_buffer *buffer;
 	enum iucv_tx_notify notification;
+	struct qeth_qdio_out_q *queue;
 	unsigned int i;
 
 	aob = (struct qaob *) phys_to_virt(phys_aob_addr);

@@ -512,7 +513,9 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
 			buffer->is_header[i] = 0;
 		}
 
+		queue = buffer->q;
 		atomic_set(&buffer->state, QETH_QDIO_BUF_EMPTY);
+		napi_schedule(&queue->napi);
 		break;
 	default:
 		WARN_ON_ONCE(1);

@@ -7235,9 +7238,7 @@ int qeth_open(struct net_device *dev)
 	card->data.state = CH_STATE_UP;
 	netif_tx_start_all_queues(dev);
 
-	napi_enable(&card->napi);
 	local_bh_disable();
-	napi_schedule(&card->napi);
 	if (IS_IQD(card)) {
 		struct qeth_qdio_out_q *queue;
 		unsigned int i;

@@ -7249,8 +7250,12 @@ int qeth_open(struct net_device *dev)
 			napi_schedule(&queue->napi);
 		}
 	}
+
+	napi_enable(&card->napi);
+	napi_schedule(&card->napi);
 	/* kick-start the NAPI softirq: */
 	local_bh_enable();
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(qeth_open);

@@ -7260,6 +7265,11 @@ int qeth_stop(struct net_device *dev)
 	struct qeth_card *card = dev->ml_priv;
 
 	QETH_CARD_TEXT(card, 4, "qethstop");
+
+	napi_disable(&card->napi);
+	cancel_delayed_work_sync(&card->buffer_reclaim_work);
+	qdio_stop_irq(CARD_DDEV(card));
+
 	if (IS_IQD(card)) {
 		struct qeth_qdio_out_q *queue;
 		unsigned int i;

@@ -7280,10 +7290,6 @@ int qeth_stop(struct net_device *dev)
 		netif_tx_disable(dev);
 	}
 
-	napi_disable(&card->napi);
-	cancel_delayed_work_sync(&card->buffer_reclaim_work);
-	qdio_stop_irq(CARD_DDEV(card));
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(qeth_stop);