media: rc: meson-ir: add timeout on idle

Meson doesn't seem to be able to generate timeout events in hardware. So
install a software timer to generate the timeout events required by the
decoders to prevent "ghost keypresses".
Reported-by: Matthias Reichl <hias@horus.com>
Tested-by: Matthias Reichl <hias@horus.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/rc/meson-ir.c

@@ -97,8 +97,7 @@ static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
 	status = readl_relaxed(ir->reg + IR_DEC_STATUS);
 	rawir.pulse = !!(status & STATUS_IR_DEC_IN);
 
-	ir_raw_event_store(ir->rc, &rawir);
-	ir_raw_event_handle(ir->rc);
+	ir_raw_event_store_with_timeout(ir->rc, &rawir);
 
 	spin_unlock(&ir->lock);
 

drivers/media/rc/rc-ir-raw.c

@@ -92,7 +92,6 @@ int ir_raw_event_store_edge(struct rc_dev *dev, bool pulse)
 {
 	ktime_t			now;
 	DEFINE_IR_RAW_EVENT(ev);
-	int			rc = 0;
 
 	if (!dev->raw)
 		return -EINVAL;
@@ -101,8 +100,33 @@ int ir_raw_event_store_edge(struct rc_dev *dev, bool pulse)
 	ev.duration = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
 	ev.pulse = !pulse;
 
+	return ir_raw_event_store_with_timeout(dev, &ev);
+}
+EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
+
+/*
+ * ir_raw_event_store_with_timeout() - pass a pulse/space duration to the raw
+ *				       ir decoders, schedule decoding and
+ *				       timeout
+ * @dev:	the struct rc_dev device descriptor
+ * @ev:		the struct ir_raw_event descriptor of the pulse/space
+ *
+ * This routine (which may be called from an interrupt context) stores a
+ * pulse/space duration for the raw ir decoding state machines, schedules
+ * decoding and generates a timeout.
+ */
+int ir_raw_event_store_with_timeout(struct rc_dev *dev, struct ir_raw_event *ev)
+{
+	ktime_t		now;
+	int		rc = 0;
+
+	if (!dev->raw)
+		return -EINVAL;
+
+	now = ktime_get();
+
 	spin_lock(&dev->raw->edge_spinlock);
-	rc = ir_raw_event_store(dev, &ev);
+	rc = ir_raw_event_store(dev, ev);
 
 	dev->raw->last_event = now;
 
@@ -117,7 +141,7 @@ int ir_raw_event_store_edge(struct rc_dev *dev, bool pulse)
 
 	return rc;
 }
-EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
+EXPORT_SYMBOL_GPL(ir_raw_event_store_with_timeout);
 
 /**
  * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing

include/media/rc-core.h

@@ -334,7 +334,9 @@ void ir_raw_event_handle(struct rc_dev *dev);
 int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev);
 int ir_raw_event_store_edge(struct rc_dev *dev, bool pulse);
 int ir_raw_event_store_with_filter(struct rc_dev *dev,
-				struct ir_raw_event *ev);
+				   struct ir_raw_event *ev);
+int ir_raw_event_store_with_timeout(struct rc_dev *dev,
+				    struct ir_raw_event *ev);
 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle);
 int ir_raw_encode_scancode(enum rc_proto protocol, u32 scancode,
 			   struct ir_raw_event *events, unsigned int max);