[alsa-devel] [PATCH] US-122L Driver, v0

[Karsten Wiese]

Am Donnerstag, 8. November 2007 schrieb Clemens Ladisch:
>  
> Why not put it together with the other QUIRK_MIDI_ symbols?
> 
> >  		break;
> > +	case QUIRK_MIDI_US122L:
> > +		umidi->usb_protocol_ops = &snd_usbmidi_122l_ops;
> >  	case QUIRK_MIDI_FIXED_ENDPOINT:
> >  		memcpy(&endpoints[0], quirk->data,
> >  		       sizeof(struct snd_usb_midi_endpoint_info));
> 
> Aaargh!  If you really want to do it this way, at least add a
> "/* fall through */" so that it's obvious that this is not a mistake.

Done here, will post again.

I'd like you to try the
  "ehci-hcd: complete iso urbs ASAP for number_of_packets != (n * 8) also"
  http://marc.info/?l=linux-usb-devel&m=119444869917392&w=2
with snd-usb-audio.

snd-usb-audio uses number_of_packets equalling multiples of 8 currently
when transfering over USB 2.0, no?
If so, with above patch that "multiples of 8"-thing could go away and
snd-usb-audio could achieve up to 8 times less userspace-activation-jitter
in low latency setups like 128 frames/period, 2 periods.

thanks,
      Karsten