[PATCH v2 7/7] media: rc: mceusb: allow the timeout to be configurable

[hias@horus.com (Matthias Reichl)]

Hi Sean,

On Wed, Apr 18, 2018 at 12:24:29PM +0100, Sean Young wrote:
> Hello Hias,
> 
> On Tue, Apr 17, 2018 at 09:14:57PM +0200, Matthias Reichl wrote:
> > On Sun, Apr 08, 2018 at 10:19:42PM +0100, Sean Young wrote:
> > > mceusb devices have a default timeout of 100ms, but this can be changed.
> > 
> > We finally added a backport of the v2 series (and also the mce_kbd
> > series) to LibreELEC yesterday and ratcher quickly received 2 bugreports
> > from users using mceusb receivers.
> > 
> > Local testing on RPi/gpio-ir and Intel NUC/ite-cir was fine, I've
> > been using the v2 series for over a week without issues on
> > LibreELEC (RPi with kernel 4.14).
> > 
> > Here are the links to the bugreports and logs:
> > https://forum.kodi.tv/showthread.php?tid=298461&pid=2726684#pid2726684
> > https://forum.kodi.tv/showthread.php?tid=298462&pid=2726690#pid2726690
> > 
> > Both users are using similar mceusb receivers:
> > 
> > Log 1:
> > [    6.418218] rc rc0: Media Center Ed. eHome Infrared Remote Transceiver (147a:e017) as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3:1.0/rc/rc0
> > [    6.418358] input: Media Center Ed. eHome Infrared Remote Transceiver (147a:e017) as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3:1.0/rc/rc0/input0
> > [    6.419443] rc rc0: lirc_dev: driver ir-lirc-codec (mceusb) registered at minor = 0
> > [    6.608114] mceusb 1-1.3:1.0: Registered Formosa21 SnowflakeEmulation with mce emulator interface version 1
> > [    6.608125] mceusb 1-1.3:1.0: 0 tx ports (0x0 cabled) and 1 rx sensors (0x1 active)
> > 
> > Log 2:
> > [    3.023361] rc rc0: Media Center Ed. eHome Infrared Remote Transceiver (147a:e03e) as /devices/pci0000:00/0000:00:14.0/usb1/1-10/1-10:1.0/rc/rc0
> > [    3.023393] input: Media Center Ed. eHome Infrared Remote Transceiver (147a:e03e) as /devices/pci0000:00/0000:00:14.0/usb1/1-10/1-10:1.0/rc/rc0/input11
> > [    3.023868] rc rc0: lirc_dev: driver ir-lirc-codec (mceusb) registered at minor = 0
> > [    3.119384] input: eventlircd as /devices/virtual/input/input21
> > [    3.138625] ip6_tables: (C) 2000-2006 Netfilter Core Team
> > [    3.196830] mceusb 1-10:1.0: Registered Formosa21 eHome Infrared Transceiver with mce emulator interface version 2
> > [    3.196836] mceusb 1-10:1.0: 0 tx ports (0x0 cabled) and 1 rx sensors (0x1 active)
> > 
> > In both cases ir-keytable doesn't report any scancodes and the
> > ir-ctl -r output contains very odd long space values where I'd expect
> > a short timeout instead:
> > 
> > gap between messages:
> > space 800
> > pulse 450
> > space 16777215
> > space 25400
> > pulse 2650
> > space 800
> > 
> > end of last message:
> > space 800
> > pulse 450
> > space 16777215
> > timeout 31750
> > 
> > This patch applied cleanly on 4.14 and the mceusb history from
> > 4.14 to media/master looked rather unsuspicious. I'm not 100% sure
> > if I might have missed a dependency when backporting the patch
> > or if this is indeed an issue of this patch on these particular
> > (or maybe some more) mceusb receivers.
> 
> Thanks again for a great bug report and analysis! So, it seems with the
> shorter timeout, some mceusb devices add a specific "timeout" code to
> the IR data stream (0x80) rather than a space. The current mceusb code
> resets the decoders in this case, causing the IR decoders to reset and
> lirc to report a space of 0xffffff.
> 
> Turns out that one of my mceusb devices also suffers from this, I don't
> know how I missed this. Anyway hopefully this will solve the problem.

Thanks a lot for the quick fix!

I can't test myself as I don't have the hardware, but we will
include the patch in tonight's LibreELEC build and I asked the
users to test it. I'll keep you posted about the outcome.

so long,

Hias

> 
> 
> Thanks
> 
> Sean
> 
> >>From 92d27b206e51993e927dc0b3aba210a621eef3d0 Mon Sep 17 00:00:00 2001
> From: Sean Young <sean@mess.org>
> Date: Wed, 18 Apr 2018 10:36:25 +0100
> Subject: [PATCH] media: rc: mceusb: IR of length 0 means IR timeout, not reset
> 
> The last usb packet with IR data will end with 0x80 (MCE_IRDATA_TRAILER).
> If we reset the decoder state at this point, IR decoding can fail.
> 
> Signed-off-by: Sean Young <sean@mess.org>
> ---
>  drivers/media/rc/mceusb.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/rc/mceusb.c b/drivers/media/rc/mceusb.c
> index c97cb2eb1c5f..5c0bf61fae26 100644
> --- a/drivers/media/rc/mceusb.c
> +++ b/drivers/media/rc/mceusb.c
> @@ -1201,7 +1201,12 @@ static void mceusb_process_ir_data(struct mceusb_dev *ir, int buf_len)
>  			if (ir->rem) {
>  				ir->parser_state = PARSE_IRDATA;
>  			} else {
> -				ir_raw_event_reset(ir->rc);
> +				init_ir_raw_event(&rawir);
> +				rawir.timeout = 1;
> +				rawir.duration = ir->rc->timeout;
> +				if (ir_raw_event_store_with_filter(ir->rc,
> +								   &rawir))
> +					event = true;
>  				ir->pulse_tunit = 0;
>  				ir->pulse_count = 0;
>  			}
> -- 
> 2.14.3
>