After getting said device, I was bummed it didn't work well in linux (or windows for that matter).

Fortunately I fould an earlier post about it.

http://alsa-devel.alsa-project.narkive.com/pr5aHEeM/rfc-patch-0-2-add-suppor...

For whatever reason, that patch has not made it into kernel. I can vouch that this patch

(with a few line change to support kernel changes in the last 3 years) does work and my

device now supports both audio input and output.

Unfortunately I have no experience in kernel development nor do I really understand the

alsa system. Since the code has been kept out of kernel, I suspect there is something

fishy about it. If in any way possible I would still like to see code that effectively does the

same thing as this patch upstreamed.

The slightly modified patch (for kernel 4.8):

--- sound/usb/pcm.c | 44 ++++++++++++++++++++++++++++++++++++-------- sound/usb/quirks-table.h | 24 ++++++++++++++++++++++++ 2 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 44d178e..19e319d 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -483,7 +483,7 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt) struct usb_host_interface *alts; struct usb_interface_descriptor *altsd; struct usb_interface *iface; - int err; + int err, need_init, i;

iface = usb_ifnum_to_if(dev, fmt->iface); if (WARN_ON(!iface)) @@ -498,12 +498,26 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)

/* close the old interface */ if (subs->interface >= 0 && subs->interface != fmt->iface) { - err = usb_set_interface(subs->dev, subs->interface, 0); - if (err < 0) { - dev_err(&dev->dev, - "%d:%d: return to setting 0 failed (%d)\n", - fmt->iface, fmt->altsetting, err); - return -EIO; + + need_init = iface->cur_altsetting != alts; + + if (need_init) { + err = usb_set_interface(dev, fmt->iface, fmt->altsetting); + if (err < 0) { + dev_err(&dev->dev, + "%d:%d: usb_set_interface failed (%d)\n", + fmt->iface, fmt->altsetting, err); + return -EIO; + } + dev_dbg(&dev->dev, "setting usb interface %d:%d\n", + fmt->iface, fmt->altsetting); + } + + for (i = 0; i < alts->desc.bNumEndpoints; ++i) { + if (alts->endpoint[i].desc.bEndpointAddress == fmt->endpoint) + alts->endpoint[i].enabled = 1; + else if (need_init) + alts->endpoint[i].enabled = 0; } subs->interface = -1; subs->altset_idx = 0; @@ -1241,12 +1255,26 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction) { struct snd_usb_stream *as = snd_pcm_substream_chip(substream); struct snd_usb_substream *subs = &as->substream[direction]; + struct usb_interface *iface; + struct usb_host_interface *cur_alts; + int i, ep_active = 0;

stop_endpoints(subs, true);

if (subs->interface >= 0 && !snd_usb_lock_shutdown(subs->stream->chip)) { - usb_set_interface(subs->dev, subs->interface, 0); + iface = usb_ifnum_to_if(subs->dev, subs->interface); + cur_alts = iface->cur_altsetting; + for (i = 0; i < cur_alts->desc.bNumEndpoints; ++i) { + if (cur_alts->endpoint[i].desc.bEndpointAddress == subs->ep_num) + cur_alts->endpoint[i].enabled = 0; + + ep_active += cur_alts->endpoint[i].enabled; + } + + if (!ep_active) + usb_set_interface(subs->dev, subs->interface, 0); + subs->interface = -1; snd_usb_unlock_shutdown(subs->stream->chip); } diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h index c60a776..2670498 100644 --- a/sound/usb/quirks-table.h +++ b/sound/usb/quirks-table.h @@ -2701,6 +2701,30 @@ YAMAHA_DEVICE(0x7010, "UB99"), .attributes = UAC_EP_CS_ATTR_SAMPLE_RATE, .endpoint = 0x01, .ep_attr = USB_ENDPOINT_XFER_ISOC, + .maxpacksize = 0x024c, + .rates = SNDRV_PCM_RATE_44100 | + SNDRV_PCM_RATE_48000, + .rate_min = 44100, + .rate_max = 48000, + .nr_rates = 2, + .rate_table = (unsigned int[]) { + 44100, 48000 + } + } + }, + { + .ifnum = 0, + .type = QUIRK_AUDIO_FIXED_ENDPOINT, + .data = &(const struct audioformat) { + .formats = SNDRV_PCM_FMTBIT_S24_3LE, + .channels = 2, + .iface = 0, + .altsetting = 1, + .altset_idx = 1, + .attributes = UAC_EP_CS_ATTR_SAMPLE_RATE, + .endpoint = 0x82, + .ep_attr = USB_ENDPOINT_XFER_ISOC, + .maxpacksize = 0x0126, .rates = SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000, .rate_min = 44100, -- 2.10.2

my asoundrc for testing purposes:

pcm.frontroute { type route slave.pcm "dmix:USB" ttable.0.0 1 ttable.1.1 1 } pcm.frontusb { type plug slave.pcm "frontroute" hint { show on description "USB front channels" } }

pcm.rearroute { type route slave.pcm "dmix:USB" ttable.0.2 1 ttable.1.3 1 } pcm.rearusb { type plug slave.pcm "rearroute" hint { show on description "USB rear channels" } }

pcm.micaroute { type route slave.pcm "dsnoop:USB" ttable.0.0 1 } pcm.mica { type plug slave.pcm "micaroute" hint { show on description "Focusrite Saffire Input 1" } }

pcm.micbroute { type route slave.pcm "dsnoop:USB" ttable.0.1 1 } pcm.micb { type plug slave.pcm "micbroute" hint { show on description "Focusrite Saffire Input 2" } }

pcm.!default { type plug slave { pcm "hw:1,0" } }

ctl.!default { type hw card 1 }

https://gist.github.com/shiona/def87540b87466fff315c4ac805c6766