ALSA: usb-audio: refactor code

Clean up the usb audio driver by factoring out a lot of functions to
separate files. Code for procfs, quirks, urbs, format parsers etc all
got a new home now.

Moved almost all special quirk handling to quirks.c and introduced new
generic functions to handle them, so the exceptions do not pollute the
whole driver.

Renamed usbaudio.c to card.c because this is what it actually does now.
Renamed usbmidi.c to midi.c for namespace clarity.
Removed more things from usbaudio.h.

The non-standard drivers were adopted accordingly.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 648 insertions, 0 deletions

diff --git a/sound/usb/card.c b/sound/usb/card.c
new file mode 100644
index 000000000000..426aabc729d9
--- /dev/null
+++ b/sound/usb/card.c
@@ -0,0 +1,648 @@
+/*
+ *   (Tentative) USB Audio Driver for ALSA
+ *
+ *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
+ *
+ *   Many codes borrowed from audio.c by
+ *          Alan Cox (alan@lxorguk.ukuu.org.uk)
+ *          Thomas Sailer (sailer@ife.ee.ethz.ch)
+ *
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ *
+ *  NOTES:
+ *
+ *   - async unlink should be used for avoiding the sleep inside lock.
+ *     2.4.22 usb-uhci seems buggy for async unlinking and results in
+ *     oops.  in such a cse, pass async_unlink=0 option.
+ *   - the linked URBs would be preferred but not used so far because of
+ *     the instability of unlinking.
+ *   - type II is not supported properly.  there is no device which supports
+ *     this type *correctly*.  SB extigy looks as if it supports, but it's
+ *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
+ */
+
+
+#include <linux/bitops.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/usb.h>
+#include <linux/moduleparam.h>
+#include <linux/mutex.h>
+#include <linux/usb/audio.h>
+
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/initval.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "midi.h"
+#include "usbmixer.h"
+#include "proc.h"
+#include "quirks.h"
+#include "endpoint.h"
+#include "helper.h"
+#include "debug.h"
+#include "pcm.h"
+#include "urb.h"
+#include "format.h"
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("USB Audio");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
+
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
+static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
+/* Vendor/product IDs for this card */
+static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
+static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
+static int nrpacks = 8;         /* max. number of packets per urb */
+static int async_unlink = 1;
+static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
+static int ignore_ctl_error;
+
+module_param_array(index, int, NULL, 0444);
+MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
+module_param_array(id, charp, NULL, 0444);
+MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
+module_param_array(enable, bool, NULL, 0444);
+MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
+module_param_array(vid, int, NULL, 0444);
+MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
+module_param_array(pid, int, NULL, 0444);
+MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
+module_param(nrpacks, int, 0644);
+MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
+module_param(async_unlink, bool, 0444);
+MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
+module_param_array(device_setup, int, NULL, 0444);
+MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
+module_param(ignore_ctl_error, bool, 0444);
+MODULE_PARM_DESC(ignore_ctl_error,
+                 "Ignore errors from USB controller for mixer interfaces.");
+
+/*
+ * we keep the snd_usb_audio_t instances by ourselves for merging
+ * the all interfaces on the same card as one sound device.
+ */
+
+static DEFINE_MUTEX(register_mutex);
+static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
+static struct usb_driver usb_audio_driver;
+
+/*
+ * disconnect streams
+ * called from snd_usb_audio_disconnect()
+ */
+static void snd_usb_stream_disconnect(struct list_head *head)
+{
+        int idx;
+        struct snd_usb_stream *as;
+        struct snd_usb_substream *subs;
+
+        as = list_entry(head, struct snd_usb_stream, list);
+        for (idx = 0; idx < 2; idx++) {
+                subs = &as->substream[idx];
+                if (!subs->num_formats)
+                        return;
+                snd_usb_release_substream_urbs(subs, 1);
+                subs->interface = -1;
+        }
+}
+
+static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
+{
+        struct usb_device *dev = chip->dev;
+        struct usb_host_interface *alts;
+        struct usb_interface_descriptor *altsd;
+        struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
+
+        if (!iface) {
+                snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
+                           dev->devnum, ctrlif, interface);
+                return -EINVAL;
+        }
+
+        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) {
+                int err = snd_usbmidi_create(chip->card, iface,
+                                             &chip->midi_list, NULL);
+                if (err < 0) {
+                        snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
+                                                dev->devnum, ctrlif, interface);
+                        return -EINVAL;
+                }
+                usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
+
+                return 0;
+        }
+
+        if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
+             altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
+            altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
+                snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
+                                        dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
+                /* skip non-supported classes */
+                return -EINVAL;
+        }
+
+        if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
+                snd_printk(KERN_ERR "low speed audio streaming not supported\n");
+                return -EINVAL;
+        }
+
+        if (! snd_usb_parse_audio_endpoints(chip, interface)) {
+                usb_set_interface(dev, interface, 0); /* reset the current interface */
+                usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+/*
+ * parse audio control descriptor and create pcm/midi streams
+ */
+static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
+{
+        struct usb_device *dev = chip->dev;
+        struct usb_host_interface *host_iface;
+        struct usb_interface_descriptor *altsd;
+        void *control_header;
+        int i, protocol;
+
+        /* find audiocontrol interface */
+        host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
+        control_header = snd_usb_find_csint_desc(host_iface->extra,
+                                                 host_iface->extralen,
+                                                 NULL, UAC_HEADER);
+        altsd = get_iface_desc(host_iface);
+        protocol = altsd->bInterfaceProtocol;
+
+        if (!control_header) {
+                snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
+                return -EINVAL;
+        }
+
+        switch (protocol) {
+        case UAC_VERSION_1: {
+                struct uac_ac_header_descriptor_v1 *h1 = control_header;
+
+                if (!h1->bInCollection) {
+                        snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
+                        return -EINVAL;
+                }
+
+                if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
+                        snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
+                        return -EINVAL;
+                }
+
+                for (i = 0; i < h1->bInCollection; i++)
+                        snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
+
+                break;
+        }
+
+        case UAC_VERSION_2: {
+                struct uac_clock_source_descriptor *cs;
+                struct usb_interface_assoc_descriptor *assoc =
+                        usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
+
+                if (!assoc) {
+                        snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
+                        return -EINVAL;
+                }
+
+                /* FIXME: for now, we expect there is at least one clock source
+                 * descriptor and we always take the first one.
+                 * We should properly support devices with multiple clock sources,
+                 * clock selectors and sample rate conversion units. */
+
+                cs = snd_usb_find_csint_desc(host_iface->extra, host_iface->extralen,
+                                                NULL, UAC_CLOCK_SOURCE);
+
+                if (!cs) {
+                        snd_printk(KERN_ERR "CLOCK_SOURCE descriptor not found\n");
+                        return -EINVAL;
+                }
+
+                chip->clock_id = cs->bClockID;
+
+                for (i = 0; i < assoc->bInterfaceCount; i++) {
+                        int intf = assoc->bFirstInterface + i;
+
+                        if (intf != ctrlif)
+                                snd_usb_create_stream(chip, ctrlif, intf);
+                }
+
+                break;
+        }
+
+        default:
+                snd_printk(KERN_ERR "unknown protocol version 0x%02x\n", protocol);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+/*
+ * free the chip instance
+ *
+ * here we have to do not much, since pcm and controls are already freed
+ *
+ */
+
+static int snd_usb_audio_free(struct snd_usb_audio *chip)
+{
+        kfree(chip);
+        return 0;
+}
+
+static int snd_usb_audio_dev_free(struct snd_device *device)
+{
+        struct snd_usb_audio *chip = device->device_data;
+        return snd_usb_audio_free(chip);
+}
+
+
+/*
+ * create a chip instance and set its names.
+ */
+static int snd_usb_audio_create(struct usb_device *dev, int idx,
+                                const struct snd_usb_audio_quirk *quirk,
+                                struct snd_usb_audio **rchip)
+{
+        struct snd_card *card;
+        struct snd_usb_audio *chip;
+        int err, len;
+        char component[14];
+        static struct snd_device_ops ops = {
+                .dev_free =     snd_usb_audio_dev_free,
+        };
+
+        *rchip = NULL;
+
+        if (snd_usb_get_speed(dev) != USB_SPEED_LOW &&
+            snd_usb_get_speed(dev) != USB_SPEED_FULL &&
+            snd_usb_get_speed(dev) != USB_SPEED_HIGH) {
+                snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
+                return -ENXIO;
+        }
+
+        err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
+        if (err < 0) {
+                snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
+                return err;
+        }
+
+        chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+        if (! chip) {
+                snd_card_free(card);
+                return -ENOMEM;
+        }
+
+        chip->index = idx;
+        chip->dev = dev;
+        chip->card = card;
+        chip->setup = device_setup[idx];
+        chip->nrpacks = nrpacks;
+        chip->async_unlink = async_unlink;
+
+        chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
+                              le16_to_cpu(dev->descriptor.idProduct));
+        INIT_LIST_HEAD(&chip->pcm_list);
+        INIT_LIST_HEAD(&chip->midi_list);
+        INIT_LIST_HEAD(&chip->mixer_list);
+
+        if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
+                snd_usb_audio_free(chip);
+                snd_card_free(card);
+                return err;
+        }
+
+        strcpy(card->driver, "USB-Audio");
+        sprintf(component, "USB%04x:%04x",
+                USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
+        snd_component_add(card, component);
+
+        /* retrieve the device string as shortname */
+        if (quirk && quirk->product_name) {
+                strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
+        } else {
+                if (!dev->descriptor.iProduct ||
+                    usb_string(dev, dev->descriptor.iProduct,
+                    card->shortname, sizeof(card->shortname)) <= 0) {
+                        /* no name available from anywhere, so use ID */
+                        sprintf(card->shortname, "USB Device %#04x:%#04x",
+                                USB_ID_VENDOR(chip->usb_id),
+                                USB_ID_PRODUCT(chip->usb_id));
+                }
+        }
+
+        /* retrieve the vendor and device strings as longname */
+        if (quirk && quirk->vendor_name) {
+                len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
+        } else {
+                if (dev->descriptor.iManufacturer)
+                        len = usb_string(dev, dev->descriptor.iManufacturer,
+                                         card->longname, sizeof(card->longname));
+                else
+                        len = 0;
+                /* we don't really care if there isn't any vendor string */
+        }
+        if (len > 0)
+                strlcat(card->longname, " ", sizeof(card->longname));
+
+        strlcat(card->longname, card->shortname, sizeof(card->longname));
+
+        len = strlcat(card->longname, " at ", sizeof(card->longname));
+
+        if (len < sizeof(card->longname))
+                usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
+
+        strlcat(card->longname,
+                snd_usb_get_speed(dev) == USB_SPEED_LOW ? ", low speed" :
+                snd_usb_get_speed(dev) == USB_SPEED_FULL ? ", full speed" :
+                ", high speed",
+                sizeof(card->longname));
+
+        snd_usb_audio_create_proc(chip);
+
+        *rchip = chip;
+        return 0;
+}
+
+/*
+ * probe the active usb device
+ *
+ * note that this can be called multiple times per a device, when it
+ * includes multiple audio control interfaces.
+ *
+ * thus we check the usb device pointer and creates the card instance
+ * only at the first time.  the successive calls of this function will
+ * append the pcm interface to the corresponding card.
+ */
+static void *snd_usb_audio_probe(struct usb_device *dev,
+                                 struct usb_interface *intf,
+                                 const struct usb_device_id *usb_id)
+{
+        const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
+        int i, err;
+        struct snd_usb_audio *chip;
+        struct usb_host_interface *alts;
+        int ifnum;
+        u32 id;
+
+        alts = &intf->altsetting[0];
+        ifnum = get_iface_desc(alts)->bInterfaceNumber;
+        id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
+                    le16_to_cpu(dev->descriptor.idProduct));
+        if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
+                goto __err_val;
+
+        if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
+                goto __err_val;
+
+        /*
+         * found a config.  now register to ALSA
+         */
+
+        /* check whether it's already registered */
+        chip = NULL;
+        mutex_lock(&register_mutex);
+        for (i = 0; i < SNDRV_CARDS; i++) {
+                if (usb_chip[i] && usb_chip[i]->dev == dev) {
+                        if (usb_chip[i]->shutdown) {
+                                snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
+                                goto __error;
+                        }
+                        chip = usb_chip[i];
+                        break;
+                }
+        }
+        if (! chip) {
+                /* it's a fresh one.
+                 * now look for an empty slot and create a new card instance
+                 */
+                for (i = 0; i < SNDRV_CARDS; i++)
+                        if (enable[i] && ! usb_chip[i] &&
+                            (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
+                            (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
+                                if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
+                                        goto __error;
+                                }
+                                snd_card_set_dev(chip->card, &intf->dev);
+                                break;
+                        }
+                if (!chip) {
+                        printk(KERN_ERR "no available usb audio device\n");
+                        goto __error;
+                }
+        }
+
+        chip->txfr_quirk = 0;
+        err = 1; /* continue */
+        if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
+                /* need some special handlings */
+                if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
+                        goto __error;
+        }
+
+        if (err > 0) {
+                /* create normal USB audio interfaces */
+                if (snd_usb_create_streams(chip, ifnum) < 0 ||
+                    snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
+                        goto __error;
+                }
+        }
+
+        /* we are allowed to call snd_card_register() many times */
+        if (snd_card_register(chip->card) < 0) {
+                goto __error;
+        }
+
+        usb_chip[chip->index] = chip;
+        chip->num_interfaces++;
+        mutex_unlock(&register_mutex);
+        return chip;
+
+ __error:
+        if (chip && !chip->num_interfaces)
+                snd_card_free(chip->card);
+        mutex_unlock(&register_mutex);
+ __err_val:
+        return NULL;
+}
+
+/*
+ * we need to take care of counter, since disconnection can be called also
+ * many times as well as usb_audio_probe().
+ */
+static void snd_usb_audio_disconnect(struct usb_device *dev, void *ptr)
+{
+        struct snd_usb_audio *chip;
+        struct snd_card *card;
+        struct list_head *p;
+
+        if (ptr == (void *)-1L)
+                return;
+
+        chip = ptr;
+        card = chip->card;
+        mutex_lock(&register_mutex);
+        chip->shutdown = 1;
+        chip->num_interfaces--;
+        if (chip->num_interfaces <= 0) {
+                snd_card_disconnect(card);
+                /* release the pcm resources */
+                list_for_each(p, &chip->pcm_list) {
+                        snd_usb_stream_disconnect(p);
+                }
+                /* release the midi resources */
+                list_for_each(p, &chip->midi_list) {
+                        snd_usbmidi_disconnect(p);
+                }
+                /* release mixer resources */
+                list_for_each(p, &chip->mixer_list) {
+                        snd_usb_mixer_disconnect(p);
+                }
+                usb_chip[chip->index] = NULL;
+                mutex_unlock(&register_mutex);
+                snd_card_free_when_closed(card);
+        } else {
+                mutex_unlock(&register_mutex);
+        }
+}
+
+/*
+ * new 2.5 USB kernel API
+ */
+static int usb_audio_probe(struct usb_interface *intf,
+                           const struct usb_device_id *id)
+{
+        void *chip;
+        chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
+        if (chip) {
+                usb_set_intfdata(intf, chip);
+                return 0;
+        } else
+                return -EIO;
+}
+
+static void usb_audio_disconnect(struct usb_interface *intf)
+{
+        snd_usb_audio_disconnect(interface_to_usbdev(intf),
+                                 usb_get_intfdata(intf));
+}
+
+#ifdef CONFIG_PM
+static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
+{
+        struct snd_usb_audio *chip = usb_get_intfdata(intf);
+        struct list_head *p;
+        struct snd_usb_stream *as;
+
+        if (chip == (void *)-1L)
+                return 0;
+
+        snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
+        if (!chip->num_suspended_intf++) {
+                list_for_each(p, &chip->pcm_list) {
+                        as = list_entry(p, struct snd_usb_stream, list);
+                        snd_pcm_suspend_all(as->pcm);
+                }
+        }
+
+        return 0;
+}
+
+static int usb_audio_resume(struct usb_interface *intf)
+{
+        struct snd_usb_audio *chip = usb_get_intfdata(intf);
+
+        if (chip == (void *)-1L)
+                return 0;
+        if (--chip->num_suspended_intf)
+                return 0;
+        /*
+         * ALSA leaves material resumption to user space
+         * we just notify
+         */
+
+        snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
+
+        return 0;
+}
+#endif          /* CONFIG_PM */
+
+static struct usb_device_id usb_audio_ids [] = {
+#include "quirks-table.h"
+    { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
+      .bInterfaceClass = USB_CLASS_AUDIO,
+      .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
+    { }                                         /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE (usb, usb_audio_ids);
+
+/*
+ * entry point for linux usb interface
+ */
+
+static struct usb_driver usb_audio_driver = {
+        .name =         "snd-usb-audio",
+        .probe =        usb_audio_probe,
+        .disconnect =   usb_audio_disconnect,
+        .suspend =      usb_audio_suspend,
+        .resume =       usb_audio_resume,
+        .id_table =     usb_audio_ids,
+};
+
+static int __init snd_usb_audio_init(void)
+{
+        if (nrpacks < 1 || nrpacks > MAX_PACKS) {
+                printk(KERN_WARNING "invalid nrpacks value.\n");
+                return -EINVAL;
+        }
+        return usb_register(&usb_audio_driver);
+}
+
+static void __exit snd_usb_audio_cleanup(void)
+{
+        usb_deregister(&usb_audio_driver);
+}
+
+module_init(snd_usb_audio_init);
+module_exit(snd_usb_audio_cleanup);