endpoint.c 31 KB
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/*
 *   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
 *
 */

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#include <linux/gfp.h>
#include <linux/init.h>
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#include <linux/ratelimit.h>
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#include <linux/usb.h>
#include <linux/usb/audio.h>
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#include <linux/slab.h>
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#include <sound/core.h>
#include <sound/pcm.h>
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#include <sound/pcm_params.h>
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#include "usbaudio.h"
#include "helper.h"
#include "card.h"
#include "endpoint.h"
#include "pcm.h"
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#include "quirks.h"
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#define EP_FLAG_RUNNING		1
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#define EP_FLAG_STOPPING	2
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/*
 * snd_usb_endpoint is a model that abstracts everything related to an
 * USB endpoint and its streaming.
 *
 * There are functions to activate and deactivate the streaming URBs and
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 * optional callbacks to let the pcm logic handle the actual content of the
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 * packets for playback and record. Thus, the bus streaming and the audio
 * handlers are fully decoupled.
 *
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 * There are two different types of endpoints in audio applications.
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 *
 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
 * inbound and outbound traffic.
 *
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 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
 * (3 or 4 bytes).
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 *
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 * Each endpoint has to be configured prior to being used by calling
 * snd_usb_endpoint_set_params().
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 *
 * The model incorporates a reference counting, so that multiple users
 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
 * only the first user will effectively start the URBs, and only the last
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 * one to stop it will tear the URBs down again.
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 */

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/*
 * 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;
}

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

static const char *usb_error_string(int err)
{
	switch (err) {
	case -ENODEV:
		return "no device";
	case -ENOENT:
		return "endpoint not enabled";
	case -EPIPE:
		return "endpoint stalled";
	case -ENOSPC:
		return "not enough bandwidth";
	case -ESHUTDOWN:
		return "device disabled";
	case -EHOSTUNREACH:
		return "device suspended";
	case -EINVAL:
	case -EAGAIN:
	case -EFBIG:
	case -EMSGSIZE:
		return "internal error";
	default:
		return "unknown error";
	}
}

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/**
 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
 *
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 * @ep: The snd_usb_endpoint
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 *
 * Determine whether an endpoint is driven by an implicit feedback
 * data endpoint source.
 */
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int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
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{
	return  ep->sync_master &&
		ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA &&
		ep->type == SND_USB_ENDPOINT_TYPE_DATA &&
		usb_pipeout(ep->pipe);
}

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/*
 * For streaming based on information derived from sync endpoints,
 * prepare_outbound_urb_sizes() will call next_packet_size() to
 * determine the number of samples to be sent in the next packet.
 *
 * For implicit feedback, next_packet_size() is unused.
 */
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int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep)
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{
	unsigned long flags;
	int ret;

	if (ep->fill_max)
		return ep->maxframesize;

	spin_lock_irqsave(&ep->lock, flags);
	ep->phase = (ep->phase & 0xffff)
		+ (ep->freqm << ep->datainterval);
	ret = min(ep->phase >> 16, ep->maxframesize);
	spin_unlock_irqrestore(&ep->lock, flags);

	return ret;
}

static void retire_outbound_urb(struct snd_usb_endpoint *ep,
				struct snd_urb_ctx *urb_ctx)
{
	if (ep->retire_data_urb)
		ep->retire_data_urb(ep->data_subs, urb_ctx->urb);
}

static void retire_inbound_urb(struct snd_usb_endpoint *ep,
			       struct snd_urb_ctx *urb_ctx)
{
	struct urb *urb = urb_ctx->urb;

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	if (unlikely(ep->skip_packets > 0)) {
		ep->skip_packets--;
		return;
	}

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	if (ep->sync_slave)
		snd_usb_handle_sync_urb(ep->sync_slave, ep, urb);

	if (ep->retire_data_urb)
		ep->retire_data_urb(ep->data_subs, urb);
}

/*
 * Prepare a PLAYBACK urb for submission to the bus.
 */
static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
				 struct snd_urb_ctx *ctx)
{
	int i;
	struct urb *urb = ctx->urb;
	unsigned char *cp = urb->transfer_buffer;

	urb->dev = ep->chip->dev; /* we need to set this at each time */

	switch (ep->type) {
	case SND_USB_ENDPOINT_TYPE_DATA:
		if (ep->prepare_data_urb) {
			ep->prepare_data_urb(ep->data_subs, urb);
		} else {
			/* no data provider, so send silence */
			unsigned int offs = 0;
			for (i = 0; i < ctx->packets; ++i) {
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				int counts;

				if (ctx->packet_size[i])
					counts = ctx->packet_size[i];
				else
					counts = snd_usb_endpoint_next_packet_size(ep);

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				urb->iso_frame_desc[i].offset = offs * ep->stride;
				urb->iso_frame_desc[i].length = counts * ep->stride;
				offs += counts;
			}

			urb->number_of_packets = ctx->packets;
			urb->transfer_buffer_length = offs * ep->stride;
			memset(urb->transfer_buffer, ep->silence_value,
			       offs * ep->stride);
		}
		break;

	case SND_USB_ENDPOINT_TYPE_SYNC:
		if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
			/*
			 * fill the length and offset of each urb descriptor.
			 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
			 */
			urb->iso_frame_desc[0].length = 4;
			urb->iso_frame_desc[0].offset = 0;
			cp[0] = ep->freqn;
			cp[1] = ep->freqn >> 8;
			cp[2] = ep->freqn >> 16;
			cp[3] = ep->freqn >> 24;
		} else {
			/*
			 * fill the length and offset of each urb descriptor.
			 * the fixed 10.14 frequency is passed through the pipe.
			 */
			urb->iso_frame_desc[0].length = 3;
			urb->iso_frame_desc[0].offset = 0;
			cp[0] = ep->freqn >> 2;
			cp[1] = ep->freqn >> 10;
			cp[2] = ep->freqn >> 18;
		}

		break;
	}
}

/*
 * Prepare a CAPTURE or SYNC urb for submission to the bus.
 */
static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
				       struct snd_urb_ctx *urb_ctx)
{
	int i, offs;
	struct urb *urb = urb_ctx->urb;

	urb->dev = ep->chip->dev; /* we need to set this at each time */

	switch (ep->type) {
	case SND_USB_ENDPOINT_TYPE_DATA:
		offs = 0;
		for (i = 0; i < urb_ctx->packets; i++) {
			urb->iso_frame_desc[i].offset = offs;
			urb->iso_frame_desc[i].length = ep->curpacksize;
			offs += ep->curpacksize;
		}

		urb->transfer_buffer_length = offs;
		urb->number_of_packets = urb_ctx->packets;
		break;

	case SND_USB_ENDPOINT_TYPE_SYNC:
		urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
		urb->iso_frame_desc[0].offset = 0;
		break;
	}
}

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/*
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 * Send output urbs that have been prepared previously. URBs are dequeued
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 * from ep->ready_playback_urbs and in case there there aren't any available
 * or there are no packets that have been prepared, this function does
 * nothing.
 *
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 * The reason why the functionality of sending and preparing URBs is separated
 * is that host controllers don't guarantee the order in which they return
 * inbound and outbound packets to their submitters.
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 *
 * This function is only used for implicit feedback endpoints. For endpoints
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 * driven by dedicated sync endpoints, URBs are immediately re-submitted
 * from their completion handler.
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 */
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static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
{
	while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {

		unsigned long flags;
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		struct snd_usb_packet_info *uninitialized_var(packet);
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		struct snd_urb_ctx *ctx = NULL;
		struct urb *urb;
		int err, i;

		spin_lock_irqsave(&ep->lock, flags);
		if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
			packet = ep->next_packet + ep->next_packet_read_pos;
			ep->next_packet_read_pos++;
			ep->next_packet_read_pos %= MAX_URBS;

			/* take URB out of FIFO */
			if (!list_empty(&ep->ready_playback_urbs))
				ctx = list_first_entry(&ep->ready_playback_urbs,
					       struct snd_urb_ctx, ready_list);
		}
		spin_unlock_irqrestore(&ep->lock, flags);

		if (ctx == NULL)
			return;

		list_del_init(&ctx->ready_list);
		urb = ctx->urb;

		/* copy over the length information */
		for (i = 0; i < packet->packets; i++)
			ctx->packet_size[i] = packet->packet_size[i];

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		/* call the data handler to fill in playback data */
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		prepare_outbound_urb(ep, ctx);

		err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
		if (err < 0)
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			usb_audio_err(ep->chip,
				"Unable to submit urb #%d: %d (urb %p)\n",
				ctx->index, err, ctx->urb);
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		else
			set_bit(ctx->index, &ep->active_mask);
	}
}

/*
 * complete callback for urbs
 */
static void snd_complete_urb(struct urb *urb)
{
	struct snd_urb_ctx *ctx = urb->context;
	struct snd_usb_endpoint *ep = ctx->ep;
	int err;

	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
		     urb->status == -ENODEV ||		/* device removed */
		     urb->status == -ECONNRESET ||	/* unlinked */
		     urb->status == -ESHUTDOWN ||	/* device disabled */
		     ep->chip->shutdown))		/* device disconnected */
		goto exit_clear;

	if (usb_pipeout(ep->pipe)) {
		retire_outbound_urb(ep, ctx);
		/* can be stopped during retire callback */
		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
			goto exit_clear;

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		if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
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			unsigned long flags;

			spin_lock_irqsave(&ep->lock, flags);
			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
			spin_unlock_irqrestore(&ep->lock, flags);
			queue_pending_output_urbs(ep);

			goto exit_clear;
		}

		prepare_outbound_urb(ep, ctx);
	} else {
		retire_inbound_urb(ep, ctx);
		/* can be stopped during retire callback */
		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
			goto exit_clear;

		prepare_inbound_urb(ep, ctx);
	}

	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err == 0)
		return;

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	usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
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	//snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);

exit_clear:
	clear_bit(ctx->index, &ep->active_mask);
}

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/**
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 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
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 *
 * @chip: The chip
 * @alts: The USB host interface
 * @ep_num: The number of the endpoint to use
 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
 *
 * If the requested endpoint has not been added to the given chip before,
 * a new instance is created. Otherwise, a pointer to the previoulsy
 * created instance is returned. In case of any error, NULL is returned.
 *
 * New endpoints will be added to chip->ep_list and must be freed by
 * calling snd_usb_endpoint_free().
 */
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struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
					      struct usb_host_interface *alts,
					      int ep_num, int direction, int type)
{
	struct snd_usb_endpoint *ep;
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	int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
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	if (WARN_ON(!alts))
		return NULL;

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	mutex_lock(&chip->mutex);

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	list_for_each_entry(ep, &chip->ep_list, list) {
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		if (ep->ep_num == ep_num &&
		    ep->iface == alts->desc.bInterfaceNumber &&
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		    ep->altsetting == alts->desc.bAlternateSetting) {
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			usb_audio_dbg(ep->chip,
				      "Re-using EP %x in iface %d,%d @%p\n",
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					ep_num, ep->iface, ep->altsetting, ep);
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			goto __exit_unlock;
		}
	}

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	usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
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		    is_playback ? "playback" : "capture",
		    type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
		    ep_num);

	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
	if (!ep)
		goto __exit_unlock;

	ep->chip = chip;
	spin_lock_init(&ep->lock);
	ep->type = type;
	ep->ep_num = ep_num;
	ep->iface = alts->desc.bInterfaceNumber;
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	ep->altsetting = alts->desc.bAlternateSetting;
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	INIT_LIST_HEAD(&ep->ready_playback_urbs);
	ep_num &= USB_ENDPOINT_NUMBER_MASK;

	if (is_playback)
		ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
	else
		ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);

	if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
		if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
		    get_endpoint(alts, 1)->bRefresh >= 1 &&
		    get_endpoint(alts, 1)->bRefresh <= 9)
			ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
		else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
			ep->syncinterval = 1;
		else if (get_endpoint(alts, 1)->bInterval >= 1 &&
			 get_endpoint(alts, 1)->bInterval <= 16)
			ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
		else
			ep->syncinterval = 3;

		ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
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		if (chip->usb_id == USB_ID(0x0644, 0x8038) /* TEAC UD-H01 */ &&
		    ep->syncmaxsize == 4)
			ep->udh01_fb_quirk = 1;
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	}

	list_add_tail(&ep->list, &chip->ep_list);

__exit_unlock:
	mutex_unlock(&chip->mutex);

	return ep;
}

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

	do {
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		alive = bitmap_weight(&ep->active_mask, ep->nurbs);
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		if (!alive)
			break;

		schedule_timeout_uninterruptible(1);
	} while (time_before(jiffies, end_time));

	if (alive)
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		usb_audio_err(ep->chip,
			"timeout: still %d active urbs on EP #%x\n",
			alive, ep->ep_num);
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	clear_bit(EP_FLAG_STOPPING, &ep->flags);
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	return 0;
}

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/* sync the pending stop operation;
 * this function itself doesn't trigger the stop operation
 */
void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
{
	if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
		wait_clear_urbs(ep);
}

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/*
 * unlink active urbs.
 */
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static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
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{
	unsigned int i;

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

	clear_bit(EP_FLAG_RUNNING, &ep->flags);

	INIT_LIST_HEAD(&ep->ready_playback_urbs);
	ep->next_packet_read_pos = 0;
	ep->next_packet_write_pos = 0;

	for (i = 0; i < ep->nurbs; i++) {
		if (test_bit(i, &ep->active_mask)) {
			if (!test_and_set_bit(i, &ep->unlink_mask)) {
				struct urb *u = ep->urb[i].urb;
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				usb_unlink_urb(u);
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			}
		}
	}

	return 0;
}

/*
 * release an endpoint's urbs
 */
static void release_urbs(struct snd_usb_endpoint *ep, int force)
{
	int i;

	/* route incoming urbs to nirvana */
	ep->retire_data_urb = NULL;
	ep->prepare_data_urb = NULL;

	/* stop urbs */
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	deactivate_urbs(ep, force);
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	wait_clear_urbs(ep);

	for (i = 0; i < ep->nurbs; i++)
		release_urb_ctx(&ep->urb[i]);

	if (ep->syncbuf)
		usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
				  ep->syncbuf, ep->sync_dma);

	ep->syncbuf = NULL;
	ep->nurbs = 0;
}

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/*
 * configure a data endpoint
 */
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static int data_ep_set_params(struct snd_usb_endpoint *ep,
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			      snd_pcm_format_t pcm_format,
			      unsigned int channels,
			      unsigned int period_bytes,
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			      unsigned int frames_per_period,
			      unsigned int periods_per_buffer,
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			      struct audioformat *fmt,
			      struct snd_usb_endpoint *sync_ep)
{
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	unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
	unsigned int max_packs_per_period, urbs_per_period, urb_packs;
	unsigned int max_urbs, i;
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	int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
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599
600
601
	if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
		/*
		 * When operating in DSD DOP mode, the size of a sample frame
		 * in hardware differs from the actual physical format width
		 * because we need to make room for the DOP markers.
		 */
		frame_bits += channels << 3;
	}

602
603
	ep->datainterval = fmt->datainterval;
	ep->stride = frame_bits >> 3;
604
	ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0;
605

606
607
608
609
610
611
	/* assume max. frequency is 25% higher than nominal */
	ep->freqmax = ep->freqn + (ep->freqn >> 2);
	maxsize = ((ep->freqmax + 0xffff) * (frame_bits >> 3))
				>> (16 - ep->datainterval);
	/* but wMaxPacketSize might reduce this */
	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
612
613
614
615
616
617
618
619
620
621
622
		/* whatever fits into a max. size packet */
		maxsize = ep->maxpacksize;
		ep->freqmax = (maxsize / (frame_bits >> 3))
				<< (16 - ep->datainterval);
	}

	if (ep->fill_max)
		ep->curpacksize = ep->maxpacksize;
	else
		ep->curpacksize = maxsize;

623
	if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
624
		packs_per_ms = 8 >> ep->datainterval;
625
		max_packs_per_urb = MAX_PACKS_HS;
626
	} else {
627
628
		packs_per_ms = 1;
		max_packs_per_urb = MAX_PACKS;
629
	}
630
	if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
		max_packs_per_urb = min(max_packs_per_urb,
					1U << sync_ep->syncinterval);
	max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);

	/*
	 * Capture endpoints need to use small URBs because there's no way
	 * to tell in advance where the next period will end, and we don't
	 * want the next URB to complete much after the period ends.
	 *
	 * Playback endpoints with implicit sync much use the same parameters
	 * as their corresponding capture endpoint.
	 */
	if (usb_pipein(ep->pipe) ||
			snd_usb_endpoint_implicit_feedback_sink(ep)) {

646
647
648
649
650
651
652
653
654
655
656
657
658
659
		urb_packs = packs_per_ms;
		/*
		 * Wireless devices can poll at a max rate of once per 4ms.
		 * For dataintervals less than 5, increase the packet count to
		 * allow the host controller to use bursting to fill in the
		 * gaps.
		 */
		if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
			int interval = ep->datainterval;
			while (interval < 5) {
				urb_packs <<= 1;
				++interval;
			}
		}
660
		/* make capture URBs <= 1 ms and smaller than a period */
661
		urb_packs = min(max_packs_per_urb, urb_packs);
662
663
664
		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
			urb_packs >>= 1;
		ep->nurbs = MAX_URBS;
665

666
667
668
669
670
671
672
	/*
	 * Playback endpoints without implicit sync are adjusted so that
	 * a period fits as evenly as possible in the smallest number of
	 * URBs.  The total number of URBs is adjusted to the size of the
	 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
	 */
	} else {
673
		/* determine how small a packet can be */
674
675
		minsize = (ep->freqn >> (16 - ep->datainterval)) *
				(frame_bits >> 3);
676
677
678
679
680
		/* with sync from device, assume it can be 12% lower */
		if (sync_ep)
			minsize -= minsize >> 3;
		minsize = max(minsize, 1u);

681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
		/* how many packets will contain an entire ALSA period? */
		max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);

		/* how many URBs will contain a period? */
		urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
				max_packs_per_urb);
		/* how many packets are needed in each URB? */
		urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);

		/* limit the number of frames in a single URB */
		ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
					urbs_per_period);

		/* try to use enough URBs to contain an entire ALSA buffer */
		max_urbs = min((unsigned) MAX_URBS,
				MAX_QUEUE * packs_per_ms / urb_packs);
		ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
698
699
700
701
702
703
704
	}

	/* allocate and initialize data urbs */
	for (i = 0; i < ep->nurbs; i++) {
		struct snd_urb_ctx *u = &ep->urb[i];
		u->index = i;
		u->ep = ep;
705
		u->packets = urb_packs;
706
707
708
709
710
711
712
713
714
715
716
717
718
719
		u->buffer_size = maxsize * u->packets;

		if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
			u->packets++; /* for transfer delimiter */
		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
		if (!u->urb)
			goto out_of_memory;

		u->urb->transfer_buffer =
			usb_alloc_coherent(ep->chip->dev, u->buffer_size,
					   GFP_KERNEL, &u->urb->transfer_dma);
		if (!u->urb->transfer_buffer)
			goto out_of_memory;
		u->urb->pipe = ep->pipe;
720
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
721
722
723
724
725
726
727
728
729
730
731
732
733
		u->urb->interval = 1 << ep->datainterval;
		u->urb->context = u;
		u->urb->complete = snd_complete_urb;
		INIT_LIST_HEAD(&u->ready_list);
	}

	return 0;

out_of_memory:
	release_urbs(ep, 0);
	return -ENOMEM;
}

734
735
736
/*
 * configure a sync endpoint
 */
737
static int sync_ep_set_params(struct snd_usb_endpoint *ep)
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
{
	int i;

	ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
					 GFP_KERNEL, &ep->sync_dma);
	if (!ep->syncbuf)
		return -ENOMEM;

	for (i = 0; i < SYNC_URBS; i++) {
		struct snd_urb_ctx *u = &ep->urb[i];
		u->index = i;
		u->ep = ep;
		u->packets = 1;
		u->urb = usb_alloc_urb(1, GFP_KERNEL);
		if (!u->urb)
			goto out_of_memory;
		u->urb->transfer_buffer = ep->syncbuf + i * 4;
		u->urb->transfer_dma = ep->sync_dma + i * 4;
		u->urb->transfer_buffer_length = 4;
		u->urb->pipe = ep->pipe;
758
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
		u->urb->number_of_packets = 1;
		u->urb->interval = 1 << ep->syncinterval;
		u->urb->context = u;
		u->urb->complete = snd_complete_urb;
	}

	ep->nurbs = SYNC_URBS;

	return 0;

out_of_memory:
	release_urbs(ep, 0);
	return -ENOMEM;
}

774
/**
775
 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
776
 *
777
 * @ep: the snd_usb_endpoint to configure
778
779
780
 * @pcm_format: the audio fomat.
 * @channels: the number of audio channels.
 * @period_bytes: the number of bytes in one alsa period.
781
782
 * @period_frames: the number of frames in one alsa period.
 * @buffer_periods: the number of periods in one alsa buffer.
783
 * @rate: the frame rate.
784
785
 * @fmt: the USB audio format information
 * @sync_ep: the sync endpoint to use, if any
786
 *
787
 * Determine the number of URBs to be used on this endpoint.
788
789
790
 * An endpoint must be configured before it can be started.
 * An endpoint that is already running can not be reconfigured.
 */
791
int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
792
793
794
				snd_pcm_format_t pcm_format,
				unsigned int channels,
				unsigned int period_bytes,
795
796
				unsigned int period_frames,
				unsigned int buffer_periods,
797
				unsigned int rate,
798
799
800
801
802
803
				struct audioformat *fmt,
				struct snd_usb_endpoint *sync_ep)
{
	int err;

	if (ep->use_count != 0) {
804
805
806
		usb_audio_warn(ep->chip,
			 "Unable to change format on ep #%x: already in use\n",
			 ep->ep_num);
807
808
809
810
811
812
813
814
		return -EBUSY;
	}

	/* release old buffers, if any */
	release_urbs(ep, 0);

	ep->datainterval = fmt->datainterval;
	ep->maxpacksize = fmt->maxpacksize;
815
	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
816
817

	if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
818
		ep->freqn = get_usb_full_speed_rate(rate);
819
	else
820
		ep->freqn = get_usb_high_speed_rate(rate);
821
822
823
824
825
826
827
828
829

	/* calculate the frequency in 16.16 format */
	ep->freqm = ep->freqn;
	ep->freqshift = INT_MIN;

	ep->phase = 0;

	switch (ep->type) {
	case  SND_USB_ENDPOINT_TYPE_DATA:
830
		err = data_ep_set_params(ep, pcm_format, channels,
831
832
					 period_bytes, period_frames,
					 buffer_periods, fmt, sync_ep);
833
834
		break;
	case  SND_USB_ENDPOINT_TYPE_SYNC:
835
		err = sync_ep_set_params(ep);
836
837
838
839
840
		break;
	default:
		err = -EINVAL;
	}

841
842
843
	usb_audio_dbg(ep->chip,
		"Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
		ep->ep_num, ep->type, ep->nurbs, err);
844
845
846
847

	return err;
}

848
849
850
/**
 * snd_usb_endpoint_start: start an snd_usb_endpoint
 *
851
852
853
 * @ep:		the endpoint to start
 * @can_sleep:	flag indicating whether the operation is executed in
 * 		non-atomic context
854
855
 *
 * A call to this function will increment the use count of the endpoint.
856
 * In case it is not already running, the URBs for this endpoint will be
857
858
859
860
861
862
 * submitted. Otherwise, this function does nothing.
 *
 * Must be balanced to calls of snd_usb_endpoint_stop().
 *
 * Returns an error if the URB submission failed, 0 in all other cases.
 */
863
int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep)
864
865
866
867
868
869
870
871
872
873
874
{
	int err;
	unsigned int i;

	if (ep->chip->shutdown)
		return -EBADFD;

	/* already running? */
	if (++ep->use_count != 1)
		return 0;

875
	/* just to be sure */
876
	deactivate_urbs(ep, false);
877
878
879
	if (can_sleep)
		wait_clear_urbs(ep);

880
881
882
883
	ep->active_mask = 0;
	ep->unlink_mask = 0;
	ep->phase = 0;

884
885
	snd_usb_endpoint_start_quirk(ep);

886
887
888
	/*
	 * If this endpoint has a data endpoint as implicit feedback source,
	 * don't start the urbs here. Instead, mark them all as available,
889
890
	 * wait for the record urbs to return and queue the playback urbs
	 * from that context.
891
892
893
894
	 */

	set_bit(EP_FLAG_RUNNING, &ep->flags);

895
	if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
		for (i = 0; i < ep->nurbs; i++) {
			struct snd_urb_ctx *ctx = ep->urb + i;
			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
		}

		return 0;
	}

	for (i = 0; i < ep->nurbs; i++) {
		struct urb *urb = ep->urb[i].urb;

		if (snd_BUG_ON(!urb))
			goto __error;

		if (usb_pipeout(ep->pipe)) {
			prepare_outbound_urb(ep, urb->context);
		} else {
			prepare_inbound_urb(ep, urb->context);
		}

		err = usb_submit_urb(urb, GFP_ATOMIC);
		if (err < 0) {
918
919
920
			usb_audio_err(ep->chip,
				"cannot submit urb %d, error %d: %s\n",
				i, err, usb_error_string(err));
921
922
923
924
925
926
927
928
929
930
			goto __error;
		}
		set_bit(i, &ep->active_mask);
	}

	return 0;

__error:
	clear_bit(EP_FLAG_RUNNING, &ep->flags);
	ep->use_count--;
931
	deactivate_urbs(ep, false);
932
933
934
	return -EPIPE;
}

935
936
937
938
939
940
941
/**
 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
 *
 * @ep: the endpoint to stop (may be NULL)
 *
 * A call to this function will decrement the use count of the endpoint.
 * In case the last user has requested the endpoint stop, the URBs will
942
 * actually be deactivated.
943
944
 *
 * Must be balanced to calls of snd_usb_endpoint_start().
945
946
947
 *
 * The caller needs to synchronize the pending stop operation via
 * snd_usb_endpoint_sync_pending_stop().
948
 */
949
void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
950
951
952
953
954
955
956
957
{
	if (!ep)
		return;

	if (snd_BUG_ON(ep->use_count == 0))
		return;

	if (--ep->use_count == 0) {
958
		deactivate_urbs(ep, false);
959
960
961
962
		ep->data_subs = NULL;
		ep->sync_slave = NULL;
		ep->retire_data_urb = NULL;
		ep->prepare_data_urb = NULL;
963
		set_bit(EP_FLAG_STOPPING, &ep->flags);
964
965
966
	}
}

967
968
969
970
971
/**
 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
 *
 * @ep: the endpoint to deactivate
 *
972
973
 * If the endpoint is not currently in use, this functions will
 * deactivate its associated URBs.
974
975
976
 *
 * In case of any active users, this functions does nothing.
 */
977
void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
978
979
{
	if (!ep)
980
		return;
981
982

	if (ep->use_count != 0)
983
		return;
984

985
986
	deactivate_urbs(ep, true);
	wait_clear_urbs(ep);
987
988
}

989
990
991
992
993
994
995
996
997
998
999
1000
1001
/**
 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
 *
 * @ep: the endpoint to release
 *
 * This function does not care for the endpoint's use count but will tear
 * down all the streaming URBs immediately.
 */
void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
{
	release_urbs(ep, 1);
}

1002
1003
/**
 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1004
1005
1006
 *
 * @ep: the list header of the endpoint to free
 *
1007
 * This free all resources of the given ep.
1008
 */
1009
1010
1011
1012
1013
1014
1015
1016
void snd_usb_endpoint_free(struct list_head *head)
{
	struct snd_usb_endpoint *ep;

	ep = list_entry(head, struct snd_usb_endpoint, list);
	kfree(ep);
}

1017
1018
1019
1020
1021
1022
1023
1024
1025
/**
 * snd_usb_handle_sync_urb: parse an USB sync packet
 *
 * @ep: the endpoint to handle the packet
 * @sender: the sending endpoint
 * @urb: the received packet
 *
 * This function is called from the context of an endpoint that received
 * the packet and is used to let another endpoint object handle the payload.
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
 */
void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
			     struct snd_usb_endpoint *sender,
			     const struct urb *urb)
{
	int shift;
	unsigned int f;
	unsigned long flags;

	snd_BUG_ON(ep == sender);

1037
1038
	/*
	 * In case the endpoint is operating in implicit feedback mode, prepare
1039
1040
1041
	 * a new outbound URB that has the same layout as the received packet
	 * and add it to the list of pending urbs. queue_pending_output_urbs()
	 * will take care of them later.
1042
	 */
1043
	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
	    ep->use_count != 0) {

		/* implicit feedback case */
		int i, bytes = 0;
		struct snd_urb_ctx *in_ctx;
		struct snd_usb_packet_info *out_packet;

		in_ctx = urb->context;

		/* Count overall packet size */
		for (i = 0; i < in_ctx->packets; i++)
			if (urb->iso_frame_desc[i].status == 0)
				bytes += urb->iso_frame_desc[i].actual_length;

		/*
		 * skip empty packets. At least M-Audio's Fast Track Ultra stops
		 * streaming once it received a 0-byte OUT URB
		 */
		if (bytes == 0)
			return;

		spin_lock_irqsave(&ep->lock, flags);
		out_packet = ep->next_packet + ep->next_packet_write_pos;

		/*
		 * Iterate through the inbound packet and prepare the lengths
		 * for the output packet. The OUT packet we are about to send
1071
1072
1073
1074
1075
		 * will have the same amount of payload bytes per stride as the
		 * IN packet we just received. Since the actual size is scaled
		 * by the stride, use the sender stride to calculate the length
		 * in case the number of channels differ between the implicitly
		 * fed-back endpoint and the synchronizing endpoint.
1076
1077
1078
1079
1080
1081
		 */

		out_packet->packets = in_ctx->packets;
		for (i = 0; i < in_ctx->packets; i++) {
			if (urb->iso_frame_desc[i].status == 0)
				out_packet->packet_size[i] =
1082
					urb->iso_frame_desc[i].actual_length / sender->stride;
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
			else
				out_packet->packet_size[i] = 0;
		}

		ep->next_packet_write_pos++;
		ep->next_packet_write_pos %= MAX_URBS;
		spin_unlock_irqrestore(&ep->lock, flags);
		queue_pending_output_urbs(ep);

		return;
	}

1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
	/*
	 * process after playback sync complete
	 *
	 * Full speed devices report feedback values in 10.14 format as samples
	 * per frame, high speed devices in 16.16 format as samples per
	 * microframe.
	 *
	 * Because the Audio Class 1 spec was written before USB 2.0, many high
	 * speed devices use a wrong interpretation, some others use an
	 * entirely different format.
	 *
	 * Therefore, we cannot predict what format any particular device uses
	 * and must detect it automatically.
	 */
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122

	if (urb->iso_frame_desc[0].status != 0 ||
	    urb->iso_frame_desc[0].actual_length < 3)
		return;

	f = le32_to_cpup(urb->transfer_buffer);
	if (urb->iso_frame_desc[0].actual_length == 3)
		f &= 0x00ffffff;
	else
		f &= 0x0fffffff;

	if (f == 0)
		return;

1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
	if (unlikely(sender->udh01_fb_quirk)) {
		/*
		 * The TEAC UD-H01 firmware sometimes changes the feedback value
		 * by +/- 0x1.0000.
		 */
		if (f < ep->freqn - 0x8000)
			f += 0x10000;
		else if (f > ep->freqn + 0x8000)
			f -= 0x10000;
	} else if (unlikely(ep->freqshift == INT_MIN)) {
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
		/*
		 * The first time we see a feedback value, determine its format
		 * by shifting it left or right until it matches the nominal
		 * frequency value.  This assumes that the feedback does not
		 * differ from the nominal value more than +50% or -25%.
		 */
		shift = 0;
		while (f < ep->freqn - ep->freqn / 4) {
			f <<= 1;
			shift++;
		}
		while (f > ep->freqn + ep->freqn / 2) {
			f >>= 1;
			shift--;
		}
		ep->freqshift = shift;
	} else if (ep->freqshift >= 0)
		f <<= ep->freqshift;
	else
		f >>= -ep->freqshift;

	if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
		/*
		 * If the frequency looks valid, set it.
		 * This value is referred to in prepare_playback_urb().
		 */
		spin_lock_irqsave(&ep->lock, flags);
		ep->freqm = f;
		spin_unlock_irqrestore(&ep->lock, flags);
	} else {
		/*
		 * Out of range; maybe the shift value is wrong.
		 * Reset it so that we autodetect again the next time.
		 */
		ep->freqshift = INT_MIN;
	}
}