[PATCH net 0/3] s390/qeth: fixes 2020-03-10

[PATCH net 0/3] s390/qeth: fixes 2020-03-10

[Julian Wiedmann]

Hi Dave,

please apply the following patch series for qeth to netdev's net tree.

This fixes three minor issues:
1) a setup parameter gets cleared unnecessarily when the HW config
   changes,
2) insufficient error handling when initially filling the RX ring, and
3) a rarely used worker that needs to be cancelled during tear down.

Thanks,
Julian

Julian Wiedmann (3):
  s390/qeth: don't reset default_out_queue
  s390/qeth: handle error when backing RX buffer
  s390/qeth: cancel RX reclaim work earlier

 drivers/s390/net/qeth_core_main.c | 15 +++++++++------
 drivers/s390/net/qeth_l2_main.c   |  1 +
 drivers/s390/net/qeth_l3_main.c   |  1 +
 3 files changed, 11 insertions(+), 6 deletions(-)

-- 
2.17.1

[PATCH net 1/3] s390/qeth: don't reset default_out_queue

[Julian Wiedmann]

When an OSA device in prio-queue setup is reduced to 1 TX queue due to
HW restrictions, we reset its the default_out_queue to 0.

In the old code this was needed so that qeth_get_priority_queue() gets
the queue selection right. But with proper multiqueue support we already
reduced dev->real_num_tx_queues to 1, and so the stack puts all traffic
on txq 0 without even calling .ndo_select_queue.

Thus we can preserve the user's configuration, and apply it if the OSA
device later re-gains support for multiple TX queues.

Fixes: 73dc2daf110f ("s390/qeth: add TX multiqueue support for OSA devices")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 8ca85c8a01a1..2a05d13a0e79 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1204,7 +1204,6 @@ static int qeth_osa_set_output_queues(struct qeth_card *card, bool single)
 	if (count == 1)
 		dev_info(&card->gdev->dev, "Priority Queueing not supported\n");
 
-	card->qdio.default_out_queue = single ? 0 : QETH_DEFAULT_QUEUE;
 	card->qdio.no_out_queues = count;
 	return 0;
 }
-- 
2.17.1

[PATCH net 2/3] s390/qeth: handle error when backing RX buffer

[Julian Wiedmann]

qeth_init_qdio_queues() fills the RX ring with an initial set of
RX buffers. If qeth_init_input_buffer() fails to back one of the RX
buffers with memory, we need to bail out and report the error.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 2a05d13a0e79..d8f0c610396e 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -2624,12 +2624,12 @@ static int qeth_init_input_buffer(struct qeth_card *card,
 					       ETH_HLEN +
 					       sizeof(struct ipv6hdr));
 		if (!buf->rx_skb)
-			return 1;
+			return -ENOMEM;
 	}
 
 	pool_entry = qeth_find_free_buffer_pool_entry(card);
 	if (!pool_entry)
-		return 1;
+		return -ENOBUFS;
 
 	/*
 	 * since the buffer is accessed only from the input_tasklet
@@ -2674,10 +2674,15 @@ static int qeth_init_qdio_queues(struct qeth_card *card)
 	/* inbound queue */
 	qdio_reset_buffers(card->qdio.in_q->qdio_bufs, QDIO_MAX_BUFFERS_PER_Q);
 	memset(&card->rx, 0, sizeof(struct qeth_rx));
+
 	qeth_initialize_working_pool_list(card);
 	/*give only as many buffers to hardware as we have buffer pool entries*/
-	for (i = 0; i < card->qdio.in_buf_pool.buf_count - 1; ++i)
-		qeth_init_input_buffer(card, &card->qdio.in_q->bufs[i]);
+	for (i = 0; i < card->qdio.in_buf_pool.buf_count - 1; i++) {
+		rc = qeth_init_input_buffer(card, &card->qdio.in_q->bufs[i]);
+		if (rc)
+			return rc;
+	}
+
 	card->qdio.in_q->next_buf_to_init =
 		card->qdio.in_buf_pool.buf_count - 1;
 	rc = do_QDIO(CARD_DDEV(card), QDIO_FLAG_SYNC_INPUT, 0, 0,
-- 
2.17.1

[PATCH net 3/3] s390/qeth: cancel RX reclaim work earlier

[Julian Wiedmann]

When qeth's napi poll code fails to refill an entirely empty RX ring, it
kicks off buffer_reclaim_work to try again later.

Make sure that this worker is cancelled when setting the qeth device
offline. Otherwise a RX refill action can unexpectedly end up running
concurrently to bigger re-configurations (eg. resizing the buffer pool),
without any locking.

Fixes: b333293058aa ("qeth: add support for af_iucv HiperSockets transport")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 1 -
 drivers/s390/net/qeth_l2_main.c   | 1 +
 drivers/s390/net/qeth_l3_main.c   | 1 +
 3 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index d8f0c610396e..a599801d7727 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -2392,7 +2392,6 @@ static void qeth_free_qdio_queues(struct qeth_card *card)
 		return;
 
 	qeth_free_cq(card);
-	cancel_delayed_work_sync(&card->buffer_reclaim_work);
 	for (j = 0; j < QDIO_MAX_BUFFERS_PER_Q; ++j) {
 		if (card->qdio.in_q->bufs[j].rx_skb)
 			dev_kfree_skb_any(card->qdio.in_q->bufs[j].rx_skb);
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 9972d96820f3..8fb29371788b 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -284,6 +284,7 @@ static void qeth_l2_stop_card(struct qeth_card *card)
 	if (card->state == CARD_STATE_SOFTSETUP) {
 		qeth_clear_ipacmd_list(card);
 		qeth_drain_output_queues(card);
+		cancel_delayed_work_sync(&card->buffer_reclaim_work);
 		card->state = CARD_STATE_DOWN;
 	}
 
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 317d56647a4a..82f800d1d7b3 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -1178,6 +1178,7 @@ static void qeth_l3_stop_card(struct qeth_card *card)
 		qeth_l3_clear_ip_htable(card, 1);
 		qeth_clear_ipacmd_list(card);
 		qeth_drain_output_queues(card);
+		cancel_delayed_work_sync(&card->buffer_reclaim_work);
 		card->state = CARD_STATE_DOWN;
 	}
 
-- 
2.17.1

Re: [PATCH net 0/3] s390/qeth: fixes 2020-03-10

[David Miller]

From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Tue, 10 Mar 2020 18:38:00 +0100

> please apply the following patch series for qeth to netdev's net tree.
> 
> This fixes three minor issues:
> 1) a setup parameter gets cleared unnecessarily when the HW config
>    changes,
> 2) insufficient error handling when initially filling the RX ring, and
> 3) a rarely used worker that needs to be cancelled during tear down.

Series applied and queued up for -stable, thank you.