linux-kernel - [PATCH 4.17 275/336] media: rc: mce_kbd decoder: low timeout values cause double keydowns

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Date:   Wed,  1 Aug 2018 18:50:10 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Sean Young <sean@...s.org>,
        Mauro Carvalho Chehab <mchehab@...pensource.com>,
        Sasha Levin <alexander.levin@...rosoft.com>
Subject: [PATCH 4.17 275/336] media: rc: mce_kbd decoder: low timeout values cause double keydowns

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sean Young <sean@...s.org>

[ Upstream commit c421c62a4a08aba220ad7176ef4aa4b0ced9480a ]

The mce keyboard repeats pressed keys every 100ms. If the IR timeout
is set to less than that, we send key up events before the repeat
arrives, so we have key up/key down for each IR repeat.

The keyboard ends any sequence with a 0 scancode, in which case all keys
are cleared so there is no need to run the timeout timer: it only exists
for the case that the final 0 was not received.

Signed-off-by: Sean Young <sean@...s.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@...pensource.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/media/rc/ir-mce_kbd-decoder.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

--- a/drivers/media/rc/ir-mce_kbd-decoder.c
+++ b/drivers/media/rc/ir-mce_kbd-decoder.c
@@ -324,11 +324,13 @@ again:
 			scancode = data->body & 0xffff;
 			dev_dbg(&dev->dev, "keyboard data 0x%08x\n",
 				data->body);
-			if (dev->timeout)
-				delay = usecs_to_jiffies(dev->timeout / 1000);
-			else
-				delay = msecs_to_jiffies(100);
-			mod_timer(&data->rx_timeout, jiffies + delay);
+			if (scancode) {
+				delay = nsecs_to_jiffies(dev->timeout) +
+					msecs_to_jiffies(100);
+				mod_timer(&data->rx_timeout, jiffies + delay);
+			} else {
+				del_timer(&data->rx_timeout);
+			}
 			/* Pass data to keyboard buffer parser */
 			ir_mce_kbd_process_keyboard_data(dev, scancode);
 			lsc.rc_proto = RC_PROTO_MCIR2_KBD;