ALSA: snd-usb: fix cross-interface streaming devices
authorDaniel Mack <zonque@gmail.com>
Thu, 30 Aug 2012 16:52:31 +0000 (18:52 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 14 Sep 2012 16:59:41 +0000 (09:59 -0700)
commit632b4daff0c87e2a36be7b3c925e90dfc255b648
tree10f211482d90ade1679aacaf550a2ea8fe273738
parentca150f7ade5973c3bce19261bca6174d5c3cc342
ALSA: snd-usb: fix cross-interface streaming devices

commit 2e4a263ca80a203ac6109f5932722a716c265395 upstream.

Commit 68e67f40b ("ALSA: snd-usb: move calls to usb_set_interface")
saved us some unnecessary calls to snd_usb_set_interface() but ignored
the fact that there is at least one device out there which operates on
two endpoint in different interfaces simultaniously.

Take care for this by catching the case where data and sync endpoints
are located on different interfaces and calling snd_usb_set_interface()
between the start of the two endpoints.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Reported-by: Robert M. Albrecht <linux@romal.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sound/usb/pcm.c