[media] [3.3.0] ir-raw: remove BUG_ON in ir_raw_event_thread

This patch removes BUG_ON in ir_raw_event_thread which IMO is a
over-kill, and this kills the ir_raw_event_thread too. With a bit of
additional logic in this patch, we nomore need to kill this thread.
Other disadvantage of having a BUG-ON is,
wake_up_process(dev->raw->thread) called on dead thread via
ir_raw_event_handle will result in total lockup in SMP system.

Advantage of this patch is ir-raw event thread is left in a usable state
even if the fifo does not have enough bytes.

This patch sets the thread into TASK_INTERRUPTIBLE if raw-fifo has less
then sizeof(struct ir_raw_event) bytes.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/rc/ir-raw.c

@@ -46,9 +46,9 @@ static int ir_raw_event_thread(void *data)
 	while (!kthread_should_stop()) {
 
 		spin_lock_irq(&raw->lock);
-		retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev));
+		retval = kfifo_len(&raw->kfifo);
 
-		if (!retval) {
+		if (retval < sizeof(ev)) {
 			set_current_state(TASK_INTERRUPTIBLE);
 
 			if (kthread_should_stop())
@@ -59,11 +59,9 @@ static int ir_raw_event_thread(void *data)
 			continue;
 		}
 
+		retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev));
 		spin_unlock_irq(&raw->lock);
 
-
-		BUG_ON(retval != sizeof(ev));
-
 		mutex_lock(&ir_raw_handler_lock);
 		list_for_each_entry(handler, &ir_raw_handler_list, list)
 			handler->decode(raw->dev, ev);