can: slcan: Fix spinlock variant
slc_xmit is called within softirq context and locks sl->lock, but
slcan_write_wakeup is not softirq context, so we need to use
spin_[un]lock_bh!
Detected using kernel lock debugging mechanism.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index f5b16e0..dcf9196 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -322,13 +322,13 @@
if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev))
return;
- spin_lock(&sl->lock);
+ spin_lock_bh(&sl->lock);
if (sl->xleft <= 0) {
/* Now serial buffer is almost free & we can start
* transmission of another packet */
sl->dev->stats.tx_packets++;
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- spin_unlock(&sl->lock);
+ spin_unlock_bh(&sl->lock);
netif_wake_queue(sl->dev);
return;
}
@@ -336,7 +336,7 @@
actual = tty->ops->write(tty, sl->xhead, sl->xleft);
sl->xleft -= actual;
sl->xhead += actual;
- spin_unlock(&sl->lock);
+ spin_unlock_bh(&sl->lock);
}
/* Send a can_frame to a TTY queue. */