From: Julian Wiedmann jwi@linux.ibm.com
[ Upstream commit 4d19db777a2f32c9b76f6fd517ed8960576cb43e ]
Calling napi_schedule() from process context does not ensure that the NET_RX softirq is run in a timely fashion. So trigger it manually.
This is no big issue with current code. A call to ndo_open() is usually followed by a ndo_set_rx_mode() call, and for qeth this contains a spin_unlock_bh(). Except for OSN, where qeth_l2_set_rx_mode() bails out early. Nevertheless it's best to not depend on this behaviour, and just fix the issue at its source like all other drivers do. For instance see commit 83a0c6e58901 ("i40e: Invoke softirqs after napi_reschedule").
Fixes: a1c3ed4c9ca0 ("qeth: NAPI support for l2 and l3 discipline") Signed-off-by: Julian Wiedmann jwi@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/s390/net/qeth_l2_main.c | 3 +++ drivers/s390/net/qeth_l3_main.c | 3 +++ 2 files changed, 6 insertions(+)
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 22045e7d78ac3..97211f7f0cf02 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -996,7 +996,10 @@ static int __qeth_l2_open(struct net_device *dev)
if (qdio_stop_irq(card->data.ccwdev, 0) >= 0) { napi_enable(&card->napi); + local_bh_disable(); napi_schedule(&card->napi); + /* kick-start the NAPI softirq: */ + local_bh_enable(); } else rc = -EIO; return rc; diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 2cc9bc1ef1e38..0d71d2e6419af 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -3031,7 +3031,10 @@ static int __qeth_l3_open(struct net_device *dev)
if (qdio_stop_irq(card->data.ccwdev, 0) >= 0) { napi_enable(&card->napi); + local_bh_disable(); napi_schedule(&card->napi); + /* kick-start the NAPI softirq: */ + local_bh_enable(); } else rc = -EIO; return rc;