media/rc: Send sync space information on the lirc device

commit a8f29e89f2b54fbf2c52be341f149bc195b63a8b upstream.

Userspace expects to see a long space before the first pulse is sent on
the lirc device.  Currently, if a long time has passed and a new packet
is started, the lirc codec just returns and doesn't send anything.  This
makes lircd ignore many perfectly valid signals unless they are sent in
quick sucession.  When a reset event is delivered, we cannot know
anything about the duration of the space.  But it should be safe to
assume it has been a long time and we just set the duration to maximum.

Signed-off-by: Austin Lund <austin.lund@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/rc/ir-lirc-codec.c b/drivers/media/rc/ir-lirc-codec.c
index e4561264e12439a8f24f2a63e94ac2572b0d47a0..a895ed02da863509a7e39cc796522c6e87a737c6 100644 (file)
--- a/drivers/media/rc/ir-lirc-codec.c
+++ b/drivers/media/rc/ir-lirc-codec.c
@@ -42,11 +42,17 @@ static int ir_lirc_decode(struct rc_dev *dev, struct ir_raw_event ev)
                return -EINVAL;
 
        /* Packet start */
-       if (ev.reset)
-               return 0;
+       if (ev.reset) {
+               /* Userspace expects a long space event before the start of
+                * the signal to use as a sync.  This may be done with repeat
+                * packets and normal samples.  But if a reset has been sent
+                * then we assume that a long time has passed, so we send a
+                * space with the maximum time value. */
+               sample = LIRC_SPACE(LIRC_VALUE_MASK);
+               IR_dprintk(2, "delivering reset sync space to lirc_dev\n");
 
        /* Carrier reports */
-       if (ev.carrier_report) {
+       } else if (ev.carrier_report) {
                sample = LIRC_FREQUENCY(ev.carrier);
                IR_dprintk(2, "carrier report (freq: %d)\n", sample);