[alsa-devel] "https://bugtrack.alsa-project.org/alsa-bug" Tascam US122L

[Takashi Iwai]

Please don't drop Cc to ML.

At Thu, 6 Jun 2013 15:03:56 +0100,
James Miller wrote:
> I'm using us122l.  I've read this :
> https://bugzilla.kernel.org/show_bug.cgi?id=53241

OK, then try to stace and see what gives error.  Also, build your
driver with CONFIG_SND_DEBUG_VERBOSE=y and see the kernel messages,
too.

The problem looks like the mmap.  The strange thing is that the mmap
code hasn't been changed so much and it's relatively simple in
us122l.c.

> and the bug is being addressed but there seems like no change so far.  When
> you say the drivers are pretty hackish - do you think that I might be able
> to address them myself?  I am about to begin some driver programming and
> have a little previous development experience plus I'd be really stoked for
> a decent us122l driver.  If you know of any resources that might help with
> the module driver code then I'd be grateful.  Thanks.

Nothing special I know of, the standard kernel coding book like "Linux
Device Drivers" should be a good starting point to learn.


Takashi



> On Thu, Jun 6, 2013 at 2:33 PM, Takashi Iwai <tiwai at suse.de> wrote:
> 
> > At Thu, 6 Jun 2013 13:56:32 +0100,
> > James Miller wrote:
> > >
> > > Hi, I can't visit this bugtracker page (above) and am also wondering if
> > > there is any progress on the Tascam US122L.  I understand someone from
> > the
> > > kxaudio team has tried a kernel bisect but that the problem lies in the
> > > driver with a vm switch.
> > >
> > > http://www.remastersys.com/forums/index.php?topic=3013.0
> > >
> > > somewhere I read that this was an alsa problem but I found this kernel
> > > patch (referred to) and it has been suggested that it is this that is the
> > > cause.  I am not a prof. developer but might have a go at recompiling my
> > > kernel after changing the module so that I can get my soundcard working
> > > with kernel 3.8.13-rt(patch).  Do you guys know anything about this that
> > > might help me?
> > >
> > > https://patchwork.kernel.org/patch/1258951/
> >
> > Which driver are you using?  Is snd-usb-us122l or snd-usb-usx2y?
> >
> > If the patch above is really the culprit of breakage, the driver must
> > have been already broken before that and it just had worked with
> > luck.  Both drivers are pretty hackish, and need real fixes...
> >
> >
> > Takashi
> >
> 
> 
> 
> -- 
> James Stewart Miller Bsc(hons) Psych.
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>