USB audio device on Raspberry Pi - link_elf: symbol isa_dmastatus undefined

[Ian Lepore]

On Mon, 2014-05-05 at 16:47 +0200, Bernd Walter wrote:
> On Mon, May 05, 2014 at 04:33:56PM +0200, Hans Petter Selasky wrote:
> > On 05/05/14 15:50, Matthias Meyser wrote:
> > >
> > >Am 02.05.2014 18:00, schrieb Hans Petter Selasky:
> > >>On 05/01/14 17:08, Hans Petter Selasky wrote:
> > >>>On 05/01/14 01:34, Johny Mattsson wrote:
> > >>>>On 1 May 2014 00:14, Ian Lepore <ian at freebsd.org> wrote:
> > >>>>
> > >>>>>I was doing some testing on a wandboard (about twice as fast an an
> > >>>>>rpi)
> > >>>>>with
> > >>>>>more than 20k int/sec without having any problems.
> > >>>>>
> > >>>>
> > >>>>On a similar note, I've pushed an i.MX 283 (400MHz) board to above 300k
> > >>>>int/sec, on Linux. Admittedly at that point my shell wasn't what you'd
> > >>>>call
> > >>>>"responsive" however =) The ISR in that scenario was the GPIO
> > >>>>handler, so
> > >>>>probably a bit more light-weight than an audio ISR.
> > >>>
> > >>>I'll have a look and see if I can fix it.
> > >>Here is a patch (work in progress) which you can try:
> > >>http://home.selasky.org:8192/dwc_otg_isoc_support_wip.diff
> > >>
> > >>Still not working 100% reliable. Trying to figure out the last bits
> > >>and pieces.
> > >
> > >For testing it would be very helful if someone could add
> > >
> > >device sound
> > >device snd_uaudio
> > >
> > >to RPI-B kernel.
> > >
> > >Having this in BEAGLEBONE would be nice to.
> > >Perhaps this schould go in every config that supports usb.
> > >
> > 
> > Hi,
> > 
> > The following patch should make "devd" load sound.ko and snd_uaudio.ko 
> > automatically:
> > 
> > http://svnweb.freebsd.org/changeset/base/265359
> 
> This won't work unless sound.ko especting ISA in ARM kernel is fixed
> as well.
> 

This shouldn't be a problem.  The code that references isa stuff is
wrapped in #ifdef DEV_ISA, and an arm kernel build won't have that
defined.  The problem was that the makefile for building a sound module
created an opt_isa.h containing #define DEV_ISA when building for arm so
the loadable sound modules had references to isa but the driver in the
kernel didn't.

-- Ian