V4L/DVB (10939): ir-kbd-i2c: Prevent general protection fault on rmmod

The removal of the timer which polls the infrared input is racy.
Replacing the timer with a delayed work solves the problem.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/ir-kbd-i2c.c b/drivers/media/video/ir-kbd-i2c.c
index 2ee49b7ddcf02f868fe35b92d7aa30e8f5a10af6..092c7da0f37a7a534351536cd2f57ee15b01a4ab 100644 (file)
--- a/drivers/media/video/ir-kbd-i2c.c
+++ b/drivers/media/video/ir-kbd-i2c.c
@@ -279,15 +279,9 @@ static void ir_key_poll(struct IR_i2c *ir)
        }
 }
 
-static void ir_timer(unsigned long data)
-{
-       struct IR_i2c *ir = (struct IR_i2c*)data;
-       schedule_work(&ir->work);
-}
-
 static void ir_work(struct work_struct *work)
 {
-       struct IR_i2c *ir = container_of(work, struct IR_i2c, work);
+       struct IR_i2c *ir = container_of(work, struct IR_i2c, work.work);
        int polling_interval = 100;
 
        /* MSI TV@nywhere Plus requires more frequent polling
@@ -296,7 +290,7 @@ static void ir_work(struct work_struct *work)
                polling_interval = 50;
 
        ir_key_poll(ir);
-       mod_timer(&ir->timer, jiffies + msecs_to_jiffies(polling_interval));
+       schedule_delayed_work(&ir->work, msecs_to_jiffies(polling_interval));
 }
 
 /* ----------------------------------------------------------------------- */
@@ -452,11 +446,8 @@ static int ir_attach(struct i2c_adapter *adap, int addr,
               ir->input->name, ir->input->phys, adap->name);
 
        /* start polling via eventd */
-       INIT_WORK(&ir->work, ir_work);
-       init_timer(&ir->timer);
-       ir->timer.function = ir_timer;
-       ir->timer.data     = (unsigned long)ir;
-       schedule_work(&ir->work);
+       INIT_DELAYED_WORK(&ir->work, ir_work);
+       schedule_delayed_work(&ir->work, 0);
 
        return 0;
 
@@ -473,8 +464,7 @@ static int ir_detach(struct i2c_client *client)
        struct IR_i2c *ir = i2c_get_clientdata(client);
 
        /* kill outstanding polls */
-       del_timer_sync(&ir->timer);
-       flush_scheduled_work();
+       cancel_delayed_work_sync(&ir->work);
 
        /* unregister devices */
        input_unregister_device(ir->input);

diff --git a/include/media/ir-kbd-i2c.h b/include/media/ir-kbd-i2c.h
index 00fa57eb9fde928fc04d440ae39cdde2205266ee..07963d7054008be6490f79ee91a4f9740900e5d6 100644 (file)
--- a/include/media/ir-kbd-i2c.h
+++ b/include/media/ir-kbd-i2c.h
@@ -14,8 +14,7 @@ struct IR_i2c {
        /* Used to avoid fast repeating */
        unsigned char          old;
 
-       struct work_struct     work;
-       struct timer_list      timer;
+       struct delayed_work    work;
        char                   phys[32];
        int                    (*get_key)(struct IR_i2c*, u32*, u32*);
 };