At Sat, 15 Jun 2013 11:21:09 +0200, Clemens Ladisch wrote:

When the Android firmware enables the audio interfaces in accessory mode, it always declares in the control interface's baInterfaceNr array that interfaces 0 and 1 belong to the audio function. However, the accessory interface itself, if also enabled, already is at index 0 and shifts the actual audio interface numbers to 1 and 2, which prevents the PCM streaming interface from being seen by the host driver.

To get the PCM interface interface to work, detect when the descriptors point to the (for this driver useless) accessory interface, and redirect to the correct one.

Reported-by: Jeremy Rosen jeremy.rosen@openwide.fr Tested-by: Jeremy Rosen jeremy.rosen@openwide.fr Cc: stable@vger.kernel.org Signed-off-by: Clemens Ladisch clemens@ladisch.de

Thanks, applied (with a typo correction of the subject line :)

Takashi

---

sound/usb/card.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/sound/usb/card.c b/sound/usb/card.c index 563854a..5a5153c 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -148,14 +148,32 @@ static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int int return -EINVAL; }

• alts = &iface->altsetting[0];
• altsd = get_iface_desc(alts);
• /*

• * Android with both accessory and audio interfaces enabled gets the
  

• * interface numbers wrong.
  

• */
  

• if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||

•     chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
  

•    interface == 0 &&
  

•    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
  

•    altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
  

• interface = 2;
  

• iface = usb_ifnum_to_if(dev, interface);
  

• if (!iface)
  

• 	return -EINVAL;
  

• alts = &iface->altsetting[0];
  

• altsd = get_iface_desc(alts);
  

• }
• if (usb_interface_claimed(iface)) { snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n", dev->devnum, ctrlif, interface); return -EINVAL; }

• alts = &iface->altsetting[0];
• altsd = get_iface_desc(alts); if ((altsd->bInterfaceClass == USB_CLASS_AUDIO || altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) && altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {