V4L/DVB (10938): em28xx: 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>

1 files changed, 6 insertions, 16 deletions

diff --git a/drivers/media/video/em28xx/em28xx-input.c b/drivers/media/video/em28xx/em28xx-input.c
index 0443afe09ff8..a5abfd7a19f5 100644
--- a/drivers/media/video/em28xx/em28xx-input.c
+++ b/drivers/media/video/em28xx/em28xx-input.c
@@ -68,8 +68,7 @@ struct em28xx_IR {
 
         /* poll external decoder */
         int polling;
-        struct work_struct work;
-        struct timer_list timer;
+        struct delayed_work work;
         unsigned int last_toggle:1;
         unsigned int last_readcount;
         unsigned int repeat_interval;
@@ -292,32 +291,23 @@ static void em28xx_ir_handle_key(struct em28xx_IR *ir)
         return;
 }
 
-static void ir_timer(unsigned long data)
-{
-        struct em28xx_IR *ir = (struct em28xx_IR *)data;
-
-        schedule_work(&ir->work);
-}
-
 static void em28xx_ir_work(struct work_struct *work)
 {
-        struct em28xx_IR *ir = container_of(work, struct em28xx_IR, work);
+        struct em28xx_IR *ir = container_of(work, struct em28xx_IR, work.work);
 
         em28xx_ir_handle_key(ir);
-        mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling));
+        schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling));
 }
 
 static void em28xx_ir_start(struct em28xx_IR *ir)
 {
-        setup_timer(&ir->timer, ir_timer, (unsigned long)ir);
-        INIT_WORK(&ir->work, em28xx_ir_work);
-        schedule_work(&ir->work);
+        INIT_DELAYED_WORK(&ir->work, em28xx_ir_work);
+        schedule_delayed_work(&ir->work, 0);
 }
 
 static void em28xx_ir_stop(struct em28xx_IR *ir)
 {
-        del_timer_sync(&ir->timer);
-        flush_scheduled_work();
+        cancel_delayed_work_sync(&ir->work);
 }
 
 int em28xx_ir_init(struct em28xx *dev)