From 0ad7c9af3e1cbb97082062266705d6cb5fb207ee Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 20 Apr 2011 10:43:15 +0200 Subject: [PATCH] Char: moxa, fix locking in moxa_write moxa_write can be called from atomic context with irqs disabled (from ppp_async_push). Don't enable interrupts by spin_unlock_bh as this might cause deadlocks in the ppp layer. Instead, use irqsave/irqrestore spin_lock functions. Signed-off-by: Jiri Slaby Cc: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/moxa.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c index a290e9ebafe0..6255561dd2a3 100644 --- a/drivers/tty/moxa.c +++ b/drivers/tty/moxa.c @@ -1202,14 +1202,15 @@ static int moxa_write(struct tty_struct *tty, const unsigned char *buf, int count) { struct moxa_port *ch = tty->driver_data; + unsigned long flags; int len; if (ch == NULL) return 0; - spin_lock_bh(&moxa_lock); + spin_lock_irqsave(&moxa_lock, flags); len = MoxaPortWriteData(tty, buf, count); - spin_unlock_bh(&moxa_lock); + spin_unlock_irqrestore(&moxa_lock, flags); set_bit(LOWWAIT, &ch->statusflags); return len; -- 2.20.1