path: root/sound/usb/urb.c

/*
 *   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
 *
 */

#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>

#include <sound/core.h>
#include <sound/pcm.h>

#include "usbaudio.h"
#include "helper.h"
#include "card.h"
#include "urb.h"
#include "pcm.h"

/*
 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
 * this will overflow at approx 524 kHz
 */
static inline unsigned get_usb_full_speed_rate(unsigned int rate)
{
	return ((rate << 13) + 62) / 125;
}

/*
 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
 * this will overflow at approx 4 MHz
 */
static inline unsigned get_usb_high_speed_rate(unsigned int rate)
{
	return ((rate << 10) + 62) / 125;
}

/*
 * unlink active urbs.
 */
static int deactivate_urbs(struct snd_usb_substream *subs, int force, int can_sleep)
{
	struct snd_usb_audio *chip = subs->stream->chip;
	unsigned int i;
	int async;

	subs->running = 0;

	if (!force && subs->stream->chip->shutdown) /* to be sure... */
		return -EBADFD;

	async = !can_sleep && chip->async_unlink;

	if (!async && in_interrupt())
		return 0;

	for (i = 0; i < subs->nurbs; i++) {
		if (test_bit(i, &subs->active_mask)) {
			if (!test_and_set_bit(i, &subs->unlink_mask)) {
				struct urb *u = subs->dataurb[i].urb;
				if (async)
					usb_unlink_urb(u);
				else
					usb_kill_urb(u);
			}
		}
	}
	if (subs->syncpipe) {
		for (i = 0; i < SYNC_URBS; i++) {
			if (test_bit(i+16, &subs->active_mask)) {
				if (!test_and_set_bit(i+16, &subs->unlink_mask)) {
					struct urb *u = subs->syncurb[i].urb;
					if (async)
						usb_unlink_urb(u);
					else
						usb_kill_urb(u);
				}
			}
		}
	}
	return 0;
}


/*
 * release a urb data
 */
static void release_urb_ctx(struct snd_urb_ctx *u)
{
	if (u->urb) {
		if (u->buffer_size)
			usb_free_coherent(u->subs->dev, u->buffer_size,
					u->urb->transfer_buffer,
					u->urb->transfer_dma);
		usb_free_urb(u->urb);
		u->urb = NULL;
	}
}

/*
 *  wait until all urbs are processed.
 */
static int wait_clear_urbs(struct snd_usb_substream *subs)
{
	unsigned long end_time = jiffies + msecs_to_jiffies(1000);
	unsigned int i;
	int alive;

	do {
		alive = 0;
		for (i = 0; i < subs->nurbs; i++) {
			if (test_bit(i, &subs->active_mask))
				alive++;
		}
		if (subs->syncpipe) {
			for (i = 0; i < SYNC_URBS; i++) {
				if (test_bit(i + 16, &subs->active_mask))
					alive++;
			}
		}
		if (! alive)
			break;
		schedule_timeout_uninterruptible(1);
	} while (time_before(jiffies, end_time));
	if (alive)
		snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
	return 0;
}

/*
 * release a substream
 */
void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force)
{
	int i;

	/* stop urbs (to be sure) */
	deactivate_urbs(subs, force, 1);
	wait_clear_urbs(subs);

	for (i = 0; i < MAX_URBS; i++)
		release_urb_ctx(&subs->dataurb[i]);
	for (i = 0; i < SYNC_URBS; i++)
		release_urb_ctx(&subs->syncurb[i]);
	usb_free_coherent(subs->dev, SYNC_URBS * 4,
			subs->syncbuf, subs->sync_dma);
	subs->syncbuf = NULL;
	subs->nurbs = 0;
}

/*
 * complete callback from data urb
 */
static