This is a note to let you know that I've just added the patch titled s390/qeth: schedule TX NAPI on QAOB completion to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-qeth-schedule-tx-napi-on-qaob-completion.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9c6cd898e1a28572c2dfd4423d1a417c5549e8fc Author: Julian Wiedmann <jwi@xxxxxxxxxxxxx> Date: Tue Mar 9 17:52:20 2021 +0100 s390/qeth: schedule TX NAPI on QAOB completion [ Upstream commit 3e83d467a08e25b27c44c885f511624a71c84f7c ] 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 <jwi@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index 03f96177e58e..4d51c4ace8ea 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -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); @@ -511,7 +512,9 @@ static void qeth_qdio_handle_aob(struct qeth_card *card, kmem_cache_free(qeth_core_header_cache, data); } + queue = buffer->q; atomic_set(&buffer->state, QETH_QDIO_BUF_EMPTY); + napi_schedule(&queue->napi); break; default: WARN_ON_ONCE(1); @@ -7013,9 +7016,7 @@ 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; @@ -7027,8 +7028,12 @@ 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); @@ -7038,6 +7043,11 @@ 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; @@ -7058,10 +7068,6 @@ 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);