diff mbox

[12/16] isdn: pcbit: fix interruptible_sleep_on race

Message ID 1393412516-3762435-13-git-send-email-arnd@arndb.de
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Arnd Bergmann Feb. 26, 2014, 11:01 a.m. UTC
interruptible_sleep_on is racy and going away. In case of pcbit,
the driver would run into a timeout if the card is initialized
before we start waiting for it. This uses wait_event to fix the
race. In order to do this, the state machine handling for the
timeout case has to get trivially reorganized so we actually know
whether the timeout has occorred or not.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
---
 drivers/isdn/pcbit/drv.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

David Miller Feb. 26, 2014, 9:08 p.m. UTC | #1
From: Arnd Bergmann <arnd@arndb.de>
Date: Wed, 26 Feb 2014 12:01:52 +0100

> interruptible_sleep_on is racy and going away. In case of pcbit,
> the driver would run into a timeout if the card is initialized
> before we start waiting for it. This uses wait_event to fix the
> race. In order to do this, the state machine handling for the
> timeout case has to get trivially reorganized so we actually know
> whether the timeout has occorred or not.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied.
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diff mbox

Patch

diff --git a/drivers/isdn/pcbit/drv.c b/drivers/isdn/pcbit/drv.c
index 1eaf622..f02cc50 100644
--- a/drivers/isdn/pcbit/drv.c
+++ b/drivers/isdn/pcbit/drv.c
@@ -796,6 +796,7 @@  static void set_running_timeout(unsigned long ptr)
 #endif
 	dev = (struct pcbit_dev *) ptr;
 
+	dev->l2_state = L2_DOWN;
 	wake_up_interruptible(&dev->set_running_wq);
 }
 
@@ -818,7 +819,8 @@  static int set_protocol_running(struct pcbit_dev *dev)
 
 	add_timer(&dev->set_running_timer);
 
-	interruptible_sleep_on(&dev->set_running_wq);
+	wait_event(dev->set_running_wq, dev->l2_state == L2_RUNNING ||
+					dev->l2_state == L2_DOWN);
 
 	del_timer(&dev->set_running_timer);
 
@@ -842,8 +844,6 @@  static int set_protocol_running(struct pcbit_dev *dev)
 		printk(KERN_DEBUG "pcbit: initialization failed\n");
 		printk(KERN_DEBUG "pcbit: firmware not loaded\n");
 
-		dev->l2_state = L2_DOWN;
-
 #ifdef DEBUG
 		printk(KERN_DEBUG "Bank3 = %02x\n",
 		       readb(dev->sh_mem + BANK3));