s390/qeth: lock read device while queueing next buffer

[ Upstream commit 17bf8c9b3d499d5168537c98b61eb7a1fcbca6c2 ]

For calling ccw_device_start(), issue_next_read() needs to hold the
device's ccwlock.
This is satisfied for the IRQ handler path (where qeth_irq() gets called
under the ccwlock), but we need explicit locking for the initial call by
the MPC initialization.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 0a191b1..d3825cd 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -517,8 +517,7 @@ static inline int qeth_is_cq(struct qeth_card *card, unsigned int queue)
            queue == card->qdio.no_in_queues - 1;
 }
 
-
-static int qeth_issue_next_read(struct qeth_card *card)
+static int __qeth_issue_next_read(struct qeth_card *card)
 {
        int rc;
        struct qeth_cmd_buffer *iob;
@@ -549,6 +548,17 @@ static int qeth_issue_next_read(struct qeth_card *card)
        return rc;
 }
 
+static int qeth_issue_next_read(struct qeth_card *card)
+{
+       int ret;
+
+       spin_lock_irq(get_ccwdev_lock(CARD_RDEV(card)));
+       ret = __qeth_issue_next_read(card);
+       spin_unlock_irq(get_ccwdev_lock(CARD_RDEV(card)));
+
+       return ret;
+}
+
 static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card)
 {
        struct qeth_reply *reply;
@@ -1174,7 +1184,7 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm,
                return;
        if (channel == &card->read &&
            channel->state == CH_STATE_UP)
-               qeth_issue_next_read(card);
+               __qeth_issue_next_read(card);
 
        iob = channel->iob;
        index = channel->buf_no;