LIRC key unexpected repeat issues since 8.0.0

metaron · February 26, 2017 at 2:51 PM

Since upgrading my RPi to 8.0.0 from 7.95.3, I get occasional (1/10) double or tripple keypresses.
I'm using lirc-rpi and a home-wired IR receiver chip.

Alternating between left and down keys I see the following for example:

irw:
6c 0 KEY_DOWN devinput
69 0 KEY_LEFT devinput
6c 0 KEY_DOWN devinput
69 0 KEY_LEFT devinput
6c 0 KEY_DOWN devinput
69 0 KEY_LEFT devinput
69 1 KEY_LEFT devinput
69 2 KEY_LEFT devinput
6c 0 KEY_DOWN devinput

tail -f kodi.log | grep i- Key:
14:35:22.123 T:1961427712 DEBUG: LIRC: Update - NEW at 1185302:6c 0 KEY_DOWN devinput (KEY_DOWN)
14:35:22.124 T:1961427712 DEBUG: OnKey: 167 (0xa7, obc88) pressed, action is Down
14:35:22.705 T:1961427712 DEBUG: LIRC: Update - NEW at 1185884:69 0 KEY_LEFT devinput (KEY_LEFT)
14:35:22.706 T:1961427712 DEBUG: OnKey: 169 (0xa9, obc86) pressed, action is Left
14:35:23.338 T:1961427712 DEBUG: LIRC: Update - NEW at 1186516:6c 0 KEY_DOWN devinput (KEY_DOWN)
14:35:23.338 T:1961427712 DEBUG: OnKey: 167 (0xa7, obc88) pressed, action is Down
14:35:23.877 T:1961427712 DEBUG: LIRC: Update - NEW at 1187055:69 0 KEY_LEFT devinput (KEY_LEFT)
14:35:23.877 T:1961427712 DEBUG: OnKey: 169 (0xa9, obc86) pressed, action is Left
14:35:24.457 T:1961427712 DEBUG: OnKey: 169 (0xa9, obc86) pressed, action is Left
14:35:24.522 T:1961427712 DEBUG: LIRC: Update - NEW at 1187701:6c 0 KEY_DOWN devinput (KEY_DOWN)
14:35:24.522 T:1961427712 DEBUG: OnKey: 167 (0xa7, obc88) pressed, action is Down

It seems that sometimes (not always) I'm hitting a key-repeat event.
The odd thing is that I don't see the key repeat until I press the next key in the sequence (i.e. I got a left repeat immediately after pressing down in the example above).

If I press and hold a key, it starts repeating as I would expect it to.

I haven't touched my Lirc.conf file, but I do note that the 8.0.0 changelog says a 'fix' for key repeats was included in 8.0.0.

Is this likely to be a 'bug' in 8.0.0, or something wrong with my config which 8.0.0 is now exposing.
Anyone got an idea what I should do to stop these random key repeat events with 8.0.0? (Other than reverting to 7.95.3
[hr]
OK I've partially answered my own question with some digging.

When I revert to 7.95.3 irw doesn't show any key repeats until I press and hold - which is what I want.

The offending changes are:
v4l-utils: add 70-input-repeat.rules · LibreELEC/LibreELEC.tv@194f304 · GitHub (udev 1000ms > 500ms key repeat)
kodi: process all lirc repeat events · LibreELEC/LibreELEC.tv@ae5a167 · GitHub (kodi now actions all key repeats)

The main problem seems to be the change of default key repeat delay from 1000ms to 500ms in udev
I guess my Sky IR remote (configured as RAW codes) is that little bit more sensitive.

Now, assuming that some people need a 500ms repeat rate (Kwiboo for example) and I need a longer one to work with my remote...
Maybe this should be added to the LibreElec settings addon in some way?
[hr]
I'm not convinced that the gpio_ir_recv device is honouring the ir-keytable --delay commands. Setting this to 5000ms (5 sec) via the command line I still start getting rapid key repeats after about a second...
There's also this from running dmesg:

[ 16.743612] rc_core: loading out-of-tree module taints kernel.
[ 16.744874] WARNING: You are using an experimental version of the media stack.
[ 16.744874] As the driver is backported to an older kernel, it doesn't offer
[ 16.744874] enough quality for its usage in production.
[ 16.744874] Use it with care.
[ 16.744874] Latest git patches (needed if you report a bug to linux-media@vger.kernel.org
[ 16.744874] a02ff2e02bee64e9955dbfd8811874c3f3880f58 cx231xx: Fix TBS MAC reading.
[ 17.028884] Registered IR keymap rc-rc6-mce
[ 17.029645] input: gpio_ir_recv as /devices/platform/ir-receiver/rc/rc0/input0
[ 17.031957] rc rc0: gpio_ir_recv as /devices/platform/ir-receiver/rc/rc0
[ 17.218055] gpiomem-bcm2835 20200000.gpiomem: Initialised: Registers at 0x20200000
[ 17.321113] lirc_dev: IR Remote Control driver registered, major 243
[ 17.391295] rc rc0: lirc_dev: driver ir-lirc-codec (gpio-rc-recv) registered at minor = 0
[ 17.391309] IR LIRC bridge handler initialized
[ 19.842960] 8021q: 802.1Q VLAN Support v1.8
[ 20.173087] IR NEC protocol handler initialized
[ 20.268798] IR RC6 protocol handler initialized
[ 21.334897] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[ 22.640208] input: lircd-uinput as /devices/virtual/input/input2
[ 22.743397] input: eventlircd as /devices/virtual/input/input3

Not quite ready for LibreElec 'stable' ?

**HiassofT** · February 26, 2017 at 9:25 PM

Quote from metaron

I'm not convinced that the gpio_ir_recv device is honouring the ir-keytable --delay commands. Setting this to 5000ms (5 sec) via the command line I still start getting rapid key repeats after about a second...

I cannot reproduce this, this seems to be working fine here (with a Hauppauge rc5 remote).

Code

LibreELEC:~ # ir-keytable
Found /sys/class/rc/rc0/ (/dev/input/event1) with:
        Driver gpio-rc-recv, table rc-hauppauge
        Supported protocols: unknown other lirc rc-5 rc-5-sz jvc sony nec sanyo mce-kbd rc-6 sharp xmp
        Enabled protocols: lirc rc-5
        Name: gpio_ir_recv
        bus: 25, vendor/product: 0001:0001, version: 0x0100
        Repeat delay = 5000 ms, repeat period = 125 ms

Key repeats in kodi are starting after a 5 second delay.

irw output also shows the 5 second delay.

Monitoring input events (you need to stop kodi and eventlircd to do this) is also ok, note the timestamp of the second repeat.

Code

LibreELEC:~ # systemctl stop kodi
LibreELEC:~ # systemctl stop eventlircd
LibreELEC:~ # ir-keytable -t | grep KEY
1488143711.483995: event type EV_KEY(0x01) key_down: KEY_UP(0x0001)
1488143716.634673: event type EV_KEY(0x01) key_down: KEY_UP(0x0001)
1488143716.764672: event type EV_KEY(0x01) key_down: KEY_UP(0x0001)
1488143716.894673: event type EV_KEY(0x01) key_down: KEY_UP(0x0001)
1488143717.024670: event type EV_KEY(0x01) key_down: KEY_UP(0x0001)
...

so long,

Hias

metaron · April 23, 2017 at 2:14 PM

I've investigated a bit further with one of the current LibreElec Millhouse 18.0 builds. (#0422)
It seems that Kodi occationally duplicates the previous keypress, i.e. pressing left, down, left results in left, down, downleft.
(the audio 'click' which kodi plays confirms that it is actioning two keypresses then two more in quick succession even though I've only pressed a key on the remote three times)

Running irw in one screen, tail -f kodi.log | grep KEY in another and tail -f kodi.log | grep action in a third,
I can see held keypresses detected by irw (3 of), one 'KEY' event per selection on the remote (3 of), but four 'actions'.

This smacks of a kodi bug rather than a libreElec issue, so I thought I'd try to work arround the problem uisng 'advancedsettings'

I added the following to my advancedsettings.xml file
<advancedsettings>
<remotedelay>10</remotedelay>
<remoterepeat>800</remoterepeat>
</advancedsettings>

And it seems to have worked arround the problem, both on the millhouse build and LibreElec 8.0.1