Re: [Line6linux-devel] pod hd500x

[Andrej K. <de...@an...>]

On Jun 7, 2017 1:23 AM, "Hans Peter Möller" <hm...@gm...> wrote:

Thanks Andrej,
I will do that.

I also found in the ardour blog some quirk on snd-usb-audio for pod hd pro
in https://community.ardour.org/node/13646. The lsusb of the pod hd pro is
almost identical (except for the product id) from the one of the pod
hd500x.


that could work too, yes. For x3 there was a problem though, that some
binary initial setup was needed - but more importantly, for audio recording
to work, the device required an ongoing playback to. So because of this, I
had to use/extend podhd driver. But probably hd500x is more similar to
hd500, where it (at least according to sources) isn't needed. Just keep it
in mind if the device misbehaves... :)


I would try that path to, I still don't know how to apply the quirk,
apparently adding it to quirks-table.h and compiling the kernel.
I'm not sure why the whole kernel need to be compiled if only the
snd-usb-audio is the affected.
have you tried something like this?

afaik, you really only need to rebuild the one module. You can just insmod
that, and in worst case it will segfault :) Perhaps there are dependencies
causing while kernel rebuild, but I reckon if you add the new card at the
end of the quirks array, it should be binary compatible.

If it works, be sure to post the patch to kernel ! :)




On Tue, Jun 6, 2017 at 1:42 PM, Andrej Kruták <de...@an...> wrote:

> On Mon, Jun 5, 2017 at 7:16 PM, Hans Peter Möller <hm...@gm...>
> wrote:
> > The 4 EP (2 audio and 2 ctrl) match the ones from PODHD500_0 and
> PODHD500_1
> > (do you know what are the ctrl or User for??) so it appears to be simple.
>
> Not sure what you mean by "User", but the ctrl are used (well, can be
> used) to transfer stuff like effects configuration.
>
>
> >
> > Now to test if this simple edit would be enough, I assume I have to
> > uninstall the module from the kernel (line6usb comes with the kernel) and
> > then compile and follow the instructions prior it was included in the
> > kernel. Is that correct? If that's the case, what would be the best way
> to
> > uninstall the module from teh kernel?
>
> TBH, you should rather read some tutorial regarding this. This depends
> on your distribution, google for "linux module rebuild" etc.
>
>
> > I would also need to pin the kernel,
> > so no kernel update with line6usb module mess with this right?
> > thansk a lot.
> >
>
> That is the optimal solution. You can do such thing via dkms, for example.
>
> Myself, I only use the driver occasionally, so everytime I need it,
> I'll just basically do:
>
> rmmod snd_usb_podhd
> rmmod snd_usb_line6
> cd $LINUX_SRC/sound/usb/line6/ # basically you only need the one
> directory, not whole tree
> make -C /lib/modules/`uname -r`/build M=$PWD
> insmod snd-usb-line6.ko
> insmod snd-usb-podhd.ko
>
> (Of course, rmmod/insmod need to be executed as root).
>
>
> --
> Good luck,
>
> A.
>
> >
> >
> > On Sun, Jun 4, 2017 at 4:01 PM, Andrej Kruták <de...@an...> wrote:
> >>
> >> Hi there,
> >>
> >> On Thu, Jun 1, 2017 at 1:19 AM, Hans Peter Möller <hm...@gm...>
> >> wrote:
> >> >    I want to help to inlude the pod hd500x in the driver. I've never
> >> > done
> >> > some driver programming but I have done a lot of coding myself, from
> ASM
> >> > in
> >> > a PIC to php, java, javascript, vb, c, c#, etc... If you can give me
> >> > some
> >> > info to read and study it would be great to start.
> >> >
> >> > Do you use wireshark to do the reverse ingeneering stuff? I'f done
> some
> >> > basic stuff with it.
> >> >
> >> > Hope to hear from you soon.
> >> >
> >>
> >> There's not a lot of traffic here anymore, sadly - so you are veru
> >> much on your own.
> >>
> >>
> >> Anyhow, depends on what you want to do. If it's only the audio
> >> support, with a bit of luck it will be as simple as editing
> >> sound/usb/line6/podhd.c. Add LINE6_PODHD500X similarly like
> >> PODHD500_0. Check the endpoints (esp. the audio ones) match what you
> >> see in lsusb. If POD HD500X has more than 2+2 audio channels, get
> >> inspired at POD X3.
> >>
> >> If you would like to edit the presets etc., you'd have to reverse
> >> engineer the binary protocol. Basically install some USB sniffer (for
> >> me http://www.usblyzer.com/ worked fine), dump the binary stuff (from
> >> bulk endpoints) and have fun. If you cannot get any audio, you may
> >> need some control interface initialization - again check POD X3 or
> >> pod.c.
> >>
> >> I have written down steps I had to do to get POD X3 working - maybe
> >> you'll find them useful. http://andree.sk/2016/11/podx3 (there's also
> >> link to some WIP python binary protocol decoder) ... Perhaps the
> >> binary protocol is similar, in such case we could share some efforts.
> >> POD X3's is actually quite simple - but I never got the time to
> >> implement a GUI for it. Maybe if it turned out it'd be useful also for
> >> other PODs, it would be more temptin ;-)
> >>
> >> --
> >> Greetings & good luck,
> >>
> >> Andrej
> >
> >
>