[PATCH net 4/4] s390/qeth: fix notification for pending buffers during teardown

Julian Wiedmann
2021-03-09T16:53:31Z

The cited commit reworked the state machine for pending TX buffers.
In qeth_iqd_tx_complete() it turned PENDING into a transient state, and
uses NEED_QAOB for buffers that get parked while waiting for their QAOB
completion.

But it missed to adjust the check in qeth_tx_complete_buf(). So if
qeth_tx_complete_pending_bufs() is called during teardown to drain
the parked TX buffers, we no longer raise a notification for af_iucv.

Instead of updating the checked state, just move this code into
qeth_tx_complete_pending_bufs() itself. This also gets rid of the
special-case in the common TX completion path.

Fixes: 8908f36d20d8 ("s390/qeth: fix af_iucv notification race")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
---
drivers/s390/net/qeth_core_main.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index d0a56afec028..a814698387bc 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1390,9 +1390,6 @@ static void qeth_tx_complete_buf(struct qeth_qdio_out_buffer *buf, bool error,
struct qeth_qdio_out_q *queue = buf->q;
struct sk_buff *skb;

- if (atomic_read(&buf->state) == QETH_QDIO_BUF_PENDING)
- qeth_notify_skbs(queue, buf, TX_NOTIFY_GENERALERROR);
-
/* Empty buffer? */
if (buf->next_element_to_fill == 0)
return;
@@ -1465,6 +1462,9 @@ static void qeth_tx_complete_pending_bufs(struct qeth_card *card,
QETH_CARD_TEXT(card, 5, "fp");
QETH_CARD_TEXT_(card, 5, "%lx", (long) buf);

+ if (drain)
+ qeth_notify_skbs(queue, buf,
+ TX_NOTIFY_GENERALERROR);
qeth_tx_complete_buf(buf, drain, 0);

list_del(&buf->list_entry);
--
2.25.1