[media] rc: fix ghost keypresses with certain hw

With hardware that has to use ir_raw_event_store_edge to collect IR
sample durations, we were not doing an event reset unless
IR_MAX_DURATION had passed. That's around 4 seconds. So if someone
presses up, then down, with less than 4 seconds in between, they'd get
the initial up, then up and down upon pressing down.

To fix this, I've lowered the "send a reset event" logic's threshold to
the input device's REP_DELAY (defaults to 500ms), and with an
saa7134-based GPIO-driven IR receiver in a Hauppauge HVR-1150, I get
*much* better behavior out of the remote now. Special thanks to Devin
for providing the hardware to investigate this issue.

CC: stable@kernel.org
CC: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/rc/ir-raw.c b/drivers/media/rc/ir-raw.c
index 11c19d8..423ed45 100644 (file)
--- a/drivers/media/rc/ir-raw.c
+++ b/drivers/media/rc/ir-raw.c
@@ -114,18 +114,20 @@ int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type)
        s64                     delta; /* ns */
        DEFINE_IR_RAW_EVENT(ev);
        int                     rc = 0;
+       int                     delay;
 
        if (!dev->raw)
                return -EINVAL;
 
        now = ktime_get();
        delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
+       delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]);
 
        /* Check for a long duration since last event or if we're
         * being called for the first time, note that delta can't
         * possibly be negative.
         */
-       if (delta > IR_MAX_DURATION || !dev->raw->last_type)
+       if (delta > delay || !dev->raw->last_type)
                type |= IR_START_EVENT;
        else
                ev.duration = delta;