[mythtv-users] Fix found for IR receiver with mceusb in newer kernels

[Jerry Rubinow]

>
>
> On Mon, Jun 29, 2015 at 12:27 PM, Jerry Rubinow <jerrymr at gmail.com> wrote:
> > On Mon, Jun 29, 2015 at 1:04 PM, Mike Thomas <mt3 at pfw.demon.co.uk>
> wrote:
> >> On Mon, 29 Jun 2015 18:28:32 +0200
> >> Alec Leamas <leamas.alec at gmail.com> wrote:
> >>> On 29/06/15 17:31, Jerry Rubinow wrote:
> >>> > On Sun, Jun 28, 2015 at 2:50 PM, Jerry Rubinow <jerrymr at gmail.com>
> >>> > wrote:
> >>> >>
> >>> >> On Jun 28, 2015 13:36, "Alec Leamas" <leamas.alec at gmail.com> wrote:
> >>> >>>
> >>> >>> On 28/06/15 15:54, Jerry Rubinow wrote:
> >>> >>>
> >>> >>>>
> >>> >>>> Nick, it looks like 3.16, what I've been running, has that patch
> >>> >>>> integrated into the kernel driver.  I tried a clean Ubuntu 15.04
> >>> >>>> install and the problem is there as well.  Unfortunately the
> >>> >>>> bios doesn't let me disable xHCI.    I think it may be time to
> >>> >>>> visit newegg for a new ir receiver.
> >>> >>>
> >>> >>>
> >>> >>> TBH, I havn't read the complete thread. That said, I understand
> >>> >>> your situation as if the kernel decoding route is at a dead end
> >>> >>> for you (?).
> >>> >>>
> >>> >>> Note, the alternative is to let lirc decode the raw timing data.
> >>> >>> I know this has been mentioned before, but perhaps you missed
> >>> >>> this opportunity?
> >>> >>>
> >>> >>> Obviously, the existing config files doesn't work for you. One
> >>> >>> option would be to use irrecord to create a new config file after
> >>> >>> setting the protocol to 'lirc' and re-checking that mode2 still
> >>> >>> works as expected. Might work, dunno, but given that mode2 is OK
> >>> >>> for you I think you have a fair chance.
> >>> >>>
> >>> >>> Cheers!
> >>> >>>
> >>> >>> --alec
> >>> >>
> >>> >> Alec, that's probably worth trying, I'll try irrecord.  However, my
> >>> >> expectation is that the bits coming out of the driver will be
> >>> >> faulty due to something in the USB 3/xHCI implementation.
> >>> >>
> >>> >> I'll try that tonight.
> >>> >>
> >>> >> -Jerry
> >>> >
> >>> > Nope, I tried the config generated by irrecord and maybe one out of
> >>> > 10 to 20 presses would generate something it could recognize in
> >>> > irw, but usually not the key I pressed.
> >>>
> >>> But you did run irrecord successfully enough to create a config
> >>> file?! This does indeed looks strange.
> >>>
> >>> Just a double check: you don't have physical (i. e., IR) disturbances
> >>> around? Low energy/fluorescent lamps or so?
> >>
> >> Dear OP,
> >>
> >> You might like to look into the archives for my earlier comments
> >> regarding IR disturbances. Some monitors and TV sets produce enough IR
> >> on their own that you might as well give up using an infra red remote
> >> control. All my monitors and TVs fall into that category. It just so
> >> happens that the TV's own remote control protocol is transmitted in the
> >> blanks between the IR flashes given off by the back light. I couldn't
> >> find another remote control which would transmit in these bursts. I
> >> even bought a Sharp IR receiver chip to go with my Sharp TV and that
> >> didn't work. It took me weeks of trials before I eventually gave up.
> >>
> >> I settled on a Bluetooth remote control which I ordered from Maplin.
> >> This has been flawless. They are coded so it is possible to have
> >> several in one building without them conflicting. You just plug it in
> >> and it comes up as a HID input device (a keyboard and mouse). No
> >> drivers, no nothing. I have the key mappings if you want them.
> >>
> >> Cheers,
> >>
> >> Mike.
> >>
> >
> > Mike, I've been running this setup (tv, a/v receiver, etc), in this
> > room for years.  The only difference between totally working and
> > totally not working is swapping in a different frontend computer with
> > a newer version of mythbuntu.  No other moved/added/removed devices.
>
> On Mon, Jun 29, 2015 at 1:50 PM Roger Heflin <rogerheflin at gmail.com>
wrote:

> I had to modify the a kernel driver for xhci to get mine to work.
> 3.16.6 did not work without the change.
>
> I have not been able to update kernels last time I tried as the newer
> kernels don't yet have the modification included last time I checked.
>
> I think I posted the fix someplace, if not yell and I can probably
> figure out the change that I made.  Without the change lirc did "see"
> keypresses but none of it made any sense (garbled stuff).
>
>
I can verify that making Roger's change to the usb core fixes the issue.

To summarize, an older USB IR receiver will not work when plugged into a
USB2 or USB3 port that is using xHCI.  Bits will be dropped and scancodes
will not be received properly.  This is below the level of lirc or
ir-keytables.  I know it happens in 14.04 and later versions.

Patching config.c in drivers/usb/core fixes the issue (changing a line that
says n = 32 to n = 10) and compiling a new kernel.

Now my only problem is that after recompiling I no longer have any files in
/sys/class/rc.  So I can use lirc, but not ir-keytable.  A wrong kernel
config option?  Dunno.

-Jerry
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mythtv.org/pipermail/mythtv-users/attachments/20150703/a5dc7f00/attachment.html>