From: Alexander Stein Date: Tue, 15 Apr 2014 14:51:04 +0000 (+0200) Subject: can: slcan: Fix spinlock variant X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=367525c8c20a34560afe1d0c7cca52a44ccd62e9;p=openwrt%2Fstaging%2Fblogic.git 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 Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index f5b16e0e3a12..dcf9196f6316 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -322,13 +322,13 @@ static void slcan_write_wakeup(struct tty_struct *tty) 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 @@ static void slcan_write_wakeup(struct tty_struct *tty) 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. */