[mythtv-users] USB IR Receivers

[Alec Leamas]

On 03/09/15 22:23, Kirk Bocek wrote:
>
>
> On 9/3/2015 12:27 PM, Kirk Bocek wrote:

>
> Next problem. modprobing my new mceusb.ko yields a kernel crash of some
> sort:
>
> $modprobe -v mceusb
> insmod
> /lib/modules/4.1.5-100.fc21.x86_64/kernel/drivers/media/rc/rc-core.ko.xz
> insmod
> /lib/modules/4.1.5-100.fc21.x86_64/kernel/drivers/media/rc/mceusb.ko.xz
> Killed
>
> $dmesg
> ...
> [  163.692148] mceusb: module verification failed: signature and/or
> required key missing - tainting kernel
> [  163.730477] Registered IR keymap rc-rc6-mce
> [  163.730711] input: Media Center Ed. eHome Infrared Remote Transceiver
> (0471:20cc) as
> /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/rc/rc0/input8
> [  163.731422] rc0: Media Center Ed. eHome Infrared Remote Transceiver
> (0471:20cc) as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/rc/rc0
> [  163.746365] BUG: unable to handle kernel NULL pointer dereference at
> 0000000000000003
> [  163.746457] IP: [<ffffffffa064a129>] usb_endpoint_xfer_int+0x10/0x25

Here is a kernel oops. As long as this is with us, anything can happen. 
Now, the question is if you can reproduce this without your patches to 
mceusb.c. If so, this is a kernel bug which should be reported. If not, 
you need to find out (bisect?) which part of your patch which causes this.

> [  163.812088] IR LIRC bridge handler initialized

There is a *very* small chance that the lirc bridge works but not the 
input layer. I really doubt it, since the problem seems to be in the usb 
underpinnings. Still you could test this by doing:

   $ sudo echo lirc > /sys/class/rc/rc0/protocols
   $ mode2 --raw --device /dev/lirc0

and pushing some buttons. There should be printable space/pulse 
durations on stdout if it works.

BTW, while testing (loading/unloading) the module you might need to 
change 'rc0' here to whatever index the new module load allocates e. g., 
rc1 (been there, done that...) Check with dmesg().

Cheers!

--alec