endpoint.c 43 KB
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
 */

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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 "clock.h"
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#include "quirks.h"
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enum {
	EP_STATE_STOPPED,
	EP_STATE_RUNNING,
	EP_STATE_STOPPING,
};
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/* interface refcounting */
struct snd_usb_iface_ref {
	unsigned char iface;
	bool need_setup;
	int opened;
	struct list_head list;
};

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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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static inline bool ep_state_running(struct snd_usb_endpoint *ep)
{
	return atomic_read(&ep->state) == EP_STATE_RUNNING;
}

static inline bool ep_state_update(struct snd_usb_endpoint *ep, int old, int new)
{
	return atomic_cmpxchg(&ep->state, old, new) == old;
}

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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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{
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	return  ep->implicit_fb_sync && usb_pipeout(ep->pipe);
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}

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/*
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 * Return the number of samples to be sent in the next packet
 * for streaming based on information derived from sync endpoints
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 *
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 * This won't be used for implicit feedback which takes the packet size
 * returned from the sync source
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 */
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static int slave_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;
}

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/*
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 * Return the number of samples to be sent in the next packet
 * for adaptive and synchronous endpoints
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 */
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static int next_packet_size(struct snd_usb_endpoint *ep)
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{
	int ret;

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

	ep->sample_accum += ep->sample_rem;
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	if (ep->sample_accum >= ep->pps) {
		ep->sample_accum -= ep->pps;
		ret = ep->packsize[1];
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	} else {
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		ret = ep->packsize[0];
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	}

	return ret;
}

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/*
 * snd_usb_endpoint_next_packet_size: Return the number of samples to be sent
 * in the next packet
 */
int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,
				      struct snd_urb_ctx *ctx, int idx)
{
	if (ctx->packet_size[idx])
		return ctx->packet_size[idx];
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	else if (ep->sync_source)
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		return slave_next_packet_size(ep);
	else
		return next_packet_size(ep);
}

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static void call_retire_callback(struct snd_usb_endpoint *ep,
				 struct urb *urb)
{
	struct snd_usb_substream *data_subs;

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

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

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static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
				    struct snd_usb_endpoint *sender,
				    const struct urb *urb);

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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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	struct snd_usb_endpoint *sync_sink;
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	if (unlikely(ep->skip_packets > 0)) {
		ep->skip_packets--;
		return;
	}

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	sync_sink = READ_ONCE(ep->sync_sink);
	if (sync_sink)
		snd_usb_handle_sync_urb(sync_sink, ep, urb);
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	call_retire_callback(ep, urb);
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}

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static void prepare_silent_urb(struct snd_usb_endpoint *ep,
			       struct snd_urb_ctx *ctx)
{
	struct urb *urb = ctx->urb;
	unsigned int offs = 0;
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	unsigned int extra = 0;
	__le32 packet_length;
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	int i;

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	/* For tx_length_quirk, put packet length at start of packet */
	if (ep->chip->tx_length_quirk)
		extra = sizeof(packet_length);

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	for (i = 0; i < ctx->packets; ++i) {
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		unsigned int offset;
		unsigned int length;
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		int counts;

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		counts = snd_usb_endpoint_next_packet_size(ep, ctx, i);
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		length = counts * ep->stride; /* number of silent bytes */
		offset = offs * ep->stride + extra * i;
		urb->iso_frame_desc[i].offset = offset;
		urb->iso_frame_desc[i].length = length + extra;
		if (extra) {
			packet_length = cpu_to_le32(length);
			memcpy(urb->transfer_buffer + offset,
			       &packet_length, sizeof(packet_length));
		}
		memset(urb->transfer_buffer + offset + extra,
		       ep->silence_value, length);
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		offs += counts;
	}

	urb->number_of_packets = ctx->packets;
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	urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
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	ctx->queued = 0;
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}

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/*
 * Prepare a PLAYBACK urb for submission to the bus.
 */
static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
				 struct snd_urb_ctx *ctx)
{
	struct urb *urb = ctx->urb;
	unsigned char *cp = urb->transfer_buffer;
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	struct snd_usb_substream *data_subs;
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	urb->dev = ep->chip->dev; /* we need to set this at each time */

	switch (ep->type) {
	case SND_USB_ENDPOINT_TYPE_DATA:
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		data_subs = READ_ONCE(ep->data_subs);
		if (data_subs && ep->prepare_data_urb)
			ep->prepare_data_urb(data_subs, urb);
		else /* no data provider, so send silence */
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			prepare_silent_urb(ep, ctx);
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		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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/* notify an error as XRUN to the assigned PCM data substream */
static void notify_xrun(struct snd_usb_endpoint *ep)
{
	struct snd_usb_substream *data_subs;

	data_subs = READ_ONCE(ep->data_subs);
	if (data_subs && data_subs->pcm_substream)
		snd_pcm_stop_xrun(data_subs->pcm_substream);
}

static struct snd_usb_packet_info *
next_packet_fifo_enqueue(struct snd_usb_endpoint *ep)
{
	struct snd_usb_packet_info *p;

	p = ep->next_packet + (ep->next_packet_head + ep->next_packet_queued) %
		ARRAY_SIZE(ep->next_packet);
	ep->next_packet_queued++;
	return p;
}

static struct snd_usb_packet_info *
next_packet_fifo_dequeue(struct snd_usb_endpoint *ep)
{
	struct snd_usb_packet_info *p;

	p = ep->next_packet + ep->next_packet_head;
	ep->next_packet_head++;
	ep->next_packet_head %= ARRAY_SIZE(ep->next_packet);
	ep->next_packet_queued--;
	return p;
}

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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 aren't any available
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 * 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)
{
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	while (ep_state_running(ep)) {
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		unsigned long flags;
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		struct snd_usb_packet_info *packet;
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		struct snd_urb_ctx *ctx = NULL;
		int err, i;

		spin_lock_irqsave(&ep->lock, flags);
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		if (ep->next_packet_queued > 0 &&
		    !list_empty(&ep->ready_playback_urbs)) {
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			/* take URB out of FIFO */
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			ctx = list_first_entry(&ep->ready_playback_urbs,
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					       struct snd_urb_ctx, ready_list);
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			list_del_init(&ctx->ready_list);

			packet = next_packet_fifo_dequeue(ep);
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		}
		spin_unlock_irqrestore(&ep->lock, flags);

		if (ctx == NULL)
			return;

		/* 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);
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		if (err < 0) {
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			usb_audio_err(ep->chip,
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				      "Unable to submit urb #%d: %d at %s\n",
				      ctx->index, err, __func__);
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			notify_xrun(ep);
			return;
		}

		set_bit(ctx->index, &ep->active_mask);
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	}
}

/*
 * 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;
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	unsigned long flags;
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	int err;

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

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	if (unlikely(!ep_state_running(ep)))
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		goto exit_clear;

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

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		if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
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			spin_lock_irqsave(&ep->lock, flags);
			list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
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			clear_bit(ctx->index, &ep->active_mask);
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			spin_unlock_irqrestore(&ep->lock, flags);
			queue_pending_output_urbs(ep);
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			return;
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		}

		prepare_outbound_urb(ep, ctx);
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		/* can be stopped during prepare callback */
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		if (unlikely(!ep_state_running(ep)))
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			goto exit_clear;
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	} else {
		retire_inbound_urb(ep, ctx);
		/* can be stopped during retire callback */
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		if (unlikely(!ep_state_running(ep)))
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			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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	notify_xrun(ep);
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exit_clear:
	clear_bit(ctx->index, &ep->active_mask);
}

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/*
 * Find or create a refcount object for the given interface
 *
 * The objects are released altogether in snd_usb_endpoint_free_all()
 */
static struct snd_usb_iface_ref *
iface_ref_find(struct snd_usb_audio *chip, int iface)
{
	struct snd_usb_iface_ref *ip;

	list_for_each_entry(ip, &chip->iface_ref_list, list)
		if (ip->iface == iface)
			return ip;

	ip = kzalloc(sizeof(*ip), GFP_KERNEL);
	if (!ip)
		return NULL;
	ip->iface = iface;
	list_add_tail(&ip->list, &chip->iface_ref_list);
	return ip;
}

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/*
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 * Get the existing endpoint object corresponding EP
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 * Returns NULL if not present.
 */
struct snd_usb_endpoint *
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snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num)
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{
	struct snd_usb_endpoint *ep;

	list_for_each_entry(ep, &chip->ep_list, list) {
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		if (ep->ep_num == ep_num)
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			return ep;
	}
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	return NULL;
}

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#define ep_type_name(type) \
	(type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync")

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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
 * @ep_num: The number of the endpoint to use
 * @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,
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 * a new instance is created.
 *
 * Returns zero on success or a negative error code.
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 *
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 * New endpoints will be added to chip->ep_list and freed by
 * calling snd_usb_endpoint_free_all().
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 *
 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
 * bNumEndpoints > 1 beforehand.
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 */
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int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type)
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{
	struct snd_usb_endpoint *ep;
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	bool is_playback;
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	ep = snd_usb_get_endpoint(chip, ep_num);
	if (ep)
		return 0;
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	usb_audio_dbg(chip, "Creating new %s endpoint #%x\n",
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		      ep_type_name(type),
		      ep_num);
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	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
	if (!ep)
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		return -ENOMEM;
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	ep->chip = chip;
	spin_lock_init(&ep->lock);
	ep->type = type;
	ep->ep_num = ep_num;
	INIT_LIST_HEAD(&ep->ready_playback_urbs);

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

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	list_add_tail(&ep->list, &chip->ep_list);
	return 0;
}

/* Set up syncinterval and maxsyncsize for a sync EP */
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static void endpoint_set_syncinterval(struct snd_usb_audio *chip,
				      struct snd_usb_endpoint *ep)
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{
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646
647
	struct usb_host_interface *alts;
	struct usb_endpoint_descriptor *desc;

	alts = snd_usb_get_host_interface(chip, ep->iface, ep->altsetting);
	if (!alts)
		return;

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

	ep->syncmaxsize = le16_to_cpu(desc->wMaxPacketSize);
}

static bool endpoint_compatible(struct snd_usb_endpoint *ep,
				const struct audioformat *fp,
				const struct snd_pcm_hw_params *params)
{
	if (!ep->opened)
		return false;
	if (ep->cur_audiofmt != fp)
		return false;
	if (ep->cur_rate != params_rate(params) ||
	    ep->cur_format != params_format(params) ||
	    ep->cur_period_frames != params_period_size(params) ||
	    ep->cur_buffer_periods != params_periods(params))
		return false;
	return true;
}

/*
648
 * Check whether the given fp and hw params are compatible with the current
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
 * setup of the target EP for implicit feedback sync
 */
bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
				 struct snd_usb_endpoint *ep,
				 const struct audioformat *fp,
				 const struct snd_pcm_hw_params *params)
{
	bool ret;

	mutex_lock(&chip->mutex);
	ret = endpoint_compatible(ep, fp, params);
	mutex_unlock(&chip->mutex);
	return ret;
}

/*
 * snd_usb_endpoint_open: Open the endpoint
 *
 * Called from hw_params to assign the endpoint to the substream.
 * It's reference-counted, and only the first opener is allowed to set up
 * arbitrary parameters.  The later opener must be compatible with the
 * former opened parameters.
 * The endpoint needs to be closed via snd_usb_endpoint_close() later.
 *
 * Note that this function doesn't configure the endpoint.  The substream
 * needs to set it up later via snd_usb_endpoint_configure().
 */
struct snd_usb_endpoint *
snd_usb_endpoint_open(struct snd_usb_audio *chip,
678
		      const struct audioformat *fp,
679
680
681
682
683
		      const struct snd_pcm_hw_params *params,
		      bool is_sync_ep)
{
	struct snd_usb_endpoint *ep;
	int ep_num = is_sync_ep ? fp->sync_ep : fp->endpoint;
684

685
686
687
688
689
	mutex_lock(&chip->mutex);
	ep = snd_usb_get_endpoint(chip, ep_num);
	if (!ep) {
		usb_audio_err(chip, "Cannot find EP 0x%x to open\n", ep_num);
		goto unlock;
690
	}
691
692
693
694
695
696
697
698
699

	if (!ep->opened) {
		if (is_sync_ep) {
			ep->iface = fp->sync_iface;
			ep->altsetting = fp->sync_altsetting;
			ep->ep_idx = fp->sync_ep_idx;
		} else {
			ep->iface = fp->iface;
			ep->altsetting = fp->altsetting;
700
			ep->ep_idx = fp->ep_idx;
701
702
703
704
		}
		usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",
			      ep_num, ep->iface, ep->altsetting, ep->ep_idx);

705
706
707
708
709
710
		ep->iface_ref = iface_ref_find(chip, ep->iface);
		if (!ep->iface_ref) {
			ep = NULL;
			goto unlock;
		}

711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
		ep->cur_audiofmt = fp;
		ep->cur_channels = fp->channels;
		ep->cur_rate = params_rate(params);
		ep->cur_format = params_format(params);
		ep->cur_frame_bytes = snd_pcm_format_physical_width(ep->cur_format) *
			ep->cur_channels / 8;
		ep->cur_period_frames = params_period_size(params);
		ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes;
		ep->cur_buffer_periods = params_periods(params);

		if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC)
			endpoint_set_syncinterval(chip, ep);

		ep->implicit_fb_sync = fp->implicit_fb;
		ep->need_setup = true;

		usb_audio_dbg(chip, "  channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n",
			      ep->cur_channels, ep->cur_rate,
			      snd_pcm_format_name(ep->cur_format),
			      ep->cur_period_bytes, ep->cur_buffer_periods,
			      ep->implicit_fb_sync);

	} else {
734
735
736
737
738
		if (WARN_ON(!ep->iface_ref)) {
			ep = NULL;
			goto unlock;
		}

739
740
741
742
743
744
745
746
747
748
749
		if (!endpoint_compatible(ep, fp, params)) {
			usb_audio_err(chip, "Incompatible EP setup for 0x%x\n",
				      ep_num);
			ep = NULL;
			goto unlock;
		}

		usb_audio_dbg(chip, "Reopened EP 0x%x (count %d)\n",
			      ep_num, ep->opened);
	}

750
751
752
	if (!ep->iface_ref->opened++)
		ep->iface_ref->need_setup = true;

753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
	ep->opened++;

 unlock:
	mutex_unlock(&chip->mutex);
	return ep;
}

/*
 * snd_usb_endpoint_set_sync: Link data and sync endpoints
 *
 * Pass NULL to sync_ep to unlink again
 */
void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,
			       struct snd_usb_endpoint *data_ep,
			       struct snd_usb_endpoint *sync_ep)
{
769
	data_ep->sync_source = sync_ep;
770
771
}

772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
/*
 * Set data endpoint callbacks and the assigned data stream
 *
 * Called at PCM trigger and cleanups.
 * Pass NULL to deactivate each callback.
 */
void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,
				   void (*prepare)(struct snd_usb_substream *subs,
						   struct urb *urb),
				   void (*retire)(struct snd_usb_substream *subs,
						  struct urb *urb),
				   struct snd_usb_substream *data_subs)
{
	ep->prepare_data_urb = prepare;
	ep->retire_data_urb = retire;
	WRITE_ONCE(ep->data_subs, data_subs);
}

790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
static int endpoint_set_interface(struct snd_usb_audio *chip,
				  struct snd_usb_endpoint *ep,
				  bool set)
{
	int altset = set ? ep->altsetting : 0;
	int err;

	usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
		      ep->iface, altset, ep->ep_num);
	err = usb_set_interface(chip->dev, ep->iface, altset);
	if (err < 0) {
		usb_audio_err(chip, "%d:%d: usb_set_interface failed (%d)\n",
			      ep->iface, altset, err);
		return err;
	}

	snd_usb_set_interface_quirk(chip);
	return 0;
}

/*
 * snd_usb_endpoint_close: Close the endpoint
 *
 * Unreference the already opened endpoint via snd_usb_endpoint_open().
 */
void snd_usb_endpoint_close(struct snd_usb_audio *chip,
			    struct snd_usb_endpoint *ep)
{
	mutex_lock(&chip->mutex);
	usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",
		      ep->ep_num, ep->opened);
821
822

	if (!--ep->iface_ref->opened)
823
		endpoint_set_interface(chip, ep, false);
824
825

	if (!--ep->opened) {
826
		ep->iface = 0;
827
828
829
		ep->altsetting = 0;
		ep->cur_audiofmt = NULL;
		ep->cur_rate = 0;
830
		ep->iface_ref = NULL;
831
832
833
834
835
836
837
838
839
		usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num);
	}
	mutex_unlock(&chip->mutex);
}

/* Prepare for suspening EP, called from the main suspend handler */
void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep)
{
	ep->need_setup = true;
840
841
	if (ep->iface_ref)
		ep->iface_ref->need_setup = true;
842
843
}

844
845
846
847
848
849
850
851
/*
 *  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;

852
	if (atomic_read(&ep->state) != EP_STATE_STOPPING)
853
854
		return 0;

855
	do {
856
		alive = bitmap_weight(&ep->active_mask, ep->nurbs);
857
858
859
860
861
862
863
		if (!alive)
			break;

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

	if (alive)
864
865
866
		usb_audio_err(ep->chip,
			"timeout: still %d active urbs on EP #%x\n",
			alive, ep->ep_num);
867

868
869
870
871
	if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {
		ep->sync_sink = NULL;
		snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
	}
872

873
874
875
	return 0;
}

876
877
878
879
880
/* 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)
{
881
	if (ep)
882
883
884
		wait_clear_urbs(ep);
}

885
/*
886
 * Stop active urbs
887
 *
888
 * This function moves the EP to STOPPING state if it's being RUNNING.
889
 */
890
static int stop_urbs(struct snd_usb_endpoint *ep, bool force)
891
892
893
{
	unsigned int i;

894
	if (!force && atomic_read(&ep->running))
895
896
		return -EBUSY;

897
	if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))
898
		return 0;
899
900

	INIT_LIST_HEAD(&ep->ready_playback_urbs);
901
902
	ep->next_packet_head = 0;
	ep->next_packet_queued = 0;
903
904
905
906
907

	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;
908
				usb_unlink_urb(u);
909
910
911
912
913
914
915
916
917
918
			}
		}
	}

	return 0;
}

/*
 * release an endpoint's urbs
 */
919
static int release_urbs(struct snd_usb_endpoint *ep, bool force)
920
{
921
	int i, err;
922
923

	/* route incoming urbs to nirvana */
924
	snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
925

926
927
928
929
930
931
	/* stop and unlink urbs */
	err = stop_urbs(ep, force);
	if (err)
		return err;

	wait_clear_urbs(ep);
932
933
934
935

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

936
937
	usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
			  ep->syncbuf, ep->sync_dma);
938
939
940

	ep->syncbuf = NULL;
	ep->nurbs = 0;
941
	return 0;
942
943
}

944
945
946
/*
 * configure a data endpoint
 */
947
static int data_ep_set_params(struct snd_usb_endpoint *ep)
948
{
949
	struct snd_usb_audio *chip = ep->chip;
950
951
952
	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;
953
954
955
	const struct audioformat *fmt = ep->cur_audiofmt;
	int frame_bits = ep->cur_frame_bytes * 8;
	int tx_length_quirk = (chip->tx_length_quirk &&
956
			       usb_pipeout(ep->pipe));
957

958
959
960
961
	usb_audio_dbg(chip, "Setting params for data EP 0x%x, pipe 0x%x\n",
		      ep->ep_num, ep->pipe);

	if (ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
962
963
964
965
966
		/*
		 * 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.
		 */
967
		frame_bits += ep->cur_channels << 3;
968
969
	}

970
971
	ep->datainterval = fmt->datainterval;
	ep->stride = frame_bits >> 3;
972

973
	switch (ep->cur_format) {
974
975
976
977
978
979
980
981
982
983
984
985
986
	case SNDRV_PCM_FORMAT_U8:
		ep->silence_value = 0x80;
		break;
	case SNDRV_PCM_FORMAT_DSD_U8:
	case SNDRV_PCM_FORMAT_DSD_U16_LE:
	case SNDRV_PCM_FORMAT_DSD_U32_LE:
	case SNDRV_PCM_FORMAT_DSD_U16_BE:
	case SNDRV_PCM_FORMAT_DSD_U32_BE:
		ep->silence_value = 0x69;
		break;
	default:
		ep->silence_value = 0;
	}
987

988
989
	/* assume max. frequency is 50% higher than nominal */
	ep->freqmax = ep->freqn + (ep->freqn >> 1);
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
	/* Round up freqmax to nearest integer in order to calculate maximum
	 * packet size, which must represent a whole number of frames.
	 * This is accomplished by adding 0x0.ffff before converting the
	 * Q16.16 format into integer.
	 * In order to accurately calculate the maximum packet size when
	 * the data interval is more than 1 (i.e. ep->datainterval > 0),
	 * multiply by the data interval prior to rounding. For instance,
	 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
	 * frames with a data interval of 1, but 11 (10.25) frames with a
	 * data interval of 2.
	 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
	 * maximum datainterval value of 3, at USB full speed, higher for
	 * USB high speed, noting that ep->freqmax is in units of
	 * frames per packet in Q16.16 format.)
	 */
	maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
			 (frame_bits >> 3);
1007
1008
	if (tx_length_quirk)
		maxsize += sizeof(__le32); /* Space for length descriptor */
1009
1010
	/* but wMaxPacketSize might reduce this */
	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
1011
		/* whatever fits into a max. size packet */
1012
1013
1014
1015
1016
1017
		unsigned int data_maxsize = maxsize = ep->maxpacksize;

		if (tx_length_quirk)
			/* Need to remove the length descriptor to calc freq */
			data_maxsize -= sizeof(__le32);
		ep->freqmax = (data_maxsize / (frame_bits >> 3))
1018
1019
1020
1021
1022
1023
1024
1025
				<< (16 - ep->datainterval);
	}

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

1026
	if (snd_usb_get_speed(chip->dev) != USB_SPEED_FULL) {
1027
		packs_per_ms = 8 >> ep->datainterval;
1028
		max_packs_per_urb = MAX_PACKS_HS;
1029
	} else {
1030
1031
		packs_per_ms = 1;
		max_packs_per_urb = MAX_PACKS;
1032
	}
1033
	if (ep->sync_source && !ep->implicit_fb_sync)
1034
		max_packs_per_urb = min(max_packs_per_urb,
1035
					1U << ep->sync_source->syncinterval);
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
	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.
	 */
1046
	if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) {
1047

1048
1049
1050
1051
1052
1053
1054
		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.
		 */
1055
		if (snd_usb_get_speed(chip->dev) == USB_SPEED_WIRELESS) {
1056
1057
1058
1059
1060
1061
			int interval = ep->datainterval;
			while (interval < 5) {
				urb_packs <<= 1;
				++interval;
			}
		}
1062
		/* make capture URBs <= 1 ms and smaller than a period */
1063
		urb_packs = min(max_packs_per_urb, urb_packs);
1064
		while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes)
1065
1066
			urb_packs >>= 1;
		ep->nurbs = MAX_URBS;
1067

1068
1069
1070
1071
1072
1073
1074
	/*
	 * 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 {
1075
		/* determine how small a packet can be */
1076
1077
		minsize = (ep->freqn >> (16 - ep->datainterval)) *
				(frame_bits >> 3);
1078
		/* with sync from device, assume it can be 12% lower */
1079
		if (ep->sync_source)
1080
1081
1082
			minsize -= minsize >> 3;
		minsize = max(minsize, 1u);

1083
		/* how many packets will contain an entire ALSA period? */
1084
		max_packs_per_period = DIV_ROUND_UP(ep->cur_period_bytes, minsize);
1085
1086
1087
1088
1089
1090
1091
1092

		/* 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 */
1093
1094
		ep->max_urb_frames = DIV_ROUND_UP(ep->cur_period_frames,
						  urbs_per_period);
1095
1096
1097
1098

		/* try to use enough URBs to contain an entire ALSA buffer */
		max_urbs = min((unsigned) MAX_URBS,
				MAX_QUEUE * packs_per_ms / urb_packs);
1099
		ep->nurbs = min(max_urbs, urbs_per_period * ep->cur_buffer_periods);
1100
1101
1102
1103
1104
1105
1106
	}

	/* 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;
1107
		u->packets = urb_packs;
1108
1109
1110
1111
1112
1113
1114
1115
1116
		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 =
1117
			usb_alloc_coherent(chip->dev, u->buffer_size,
1118
1119
1120
1121
					   GFP_KERNEL, &u->urb->transfer_dma);
		if (!u->urb->transfer_buffer)
			goto out_of_memory;
		u->urb->pipe = ep->pipe;
1122
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1123
1124
1125
1126
1127
1128
		u->urb->interval = 1 << ep->datainterval;
		u->urb->context = u;
		u->urb->complete = snd_complete_urb;
		INIT_LIST_HEAD(&u->ready_list);
	}

1129
1130
1131
1132
	/* total buffer bytes of all URBs plus the next queue;
	 * referred in pcm.c
	 */
	ep->nominal_queue_size = maxsize * urb_packs * (ep->nurbs + 1);
1133
1134
1135
	return 0;

out_of_memory:
1136
	release_urbs(ep, false);
1137
1138
1139
	return -ENOMEM;
}

1140
1141
1142
/*
 * configure a sync endpoint
 */
1143
static int sync_ep_set_params(struct snd_usb_endpoint *ep)
1144
{
1145
	struct snd_usb_audio *chip = ep->chip;
1146
1147
	int i;

1148
1149
1150
1151
	usb_audio_dbg(chip, "Setting params for sync EP 0x%x, pipe 0x%x\n",
		      ep->ep_num, ep->pipe);

	ep->syncbuf = usb_alloc_coherent(chip->dev, SYNC_URBS * 4,
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
					 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;
1168
		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
		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:
1180
	release_urbs(ep, false);
1181
1182
1183
	return -ENOMEM;
}

1184
/*
1185
 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
1186
 *
1187
 * Determine the number of URBs to be used on this endpoint.
1188
1189
1190
 * An endpoint must be configured before it can be started.
 * An endpoint that is already running can not be reconfigured.
 */
1191
1192
static int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
				       struct snd_usb_endpoint *ep)
1193
{
1194
	const struct audioformat *fmt = ep->cur_audiofmt;
1195
1196
1197
	int err;

	/* release old buffers, if any */
1198
1199
1200
	err = release_urbs(ep, false);
	if (err < 0)
		return err;
1201
1202
1203

	ep->datainterval = fmt->datainterval;
	ep->maxpacksize = fmt->maxpacksize;
1204
	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
1205

1206
1207
	if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) {
		ep->freqn = get_usb_full_speed_rate(ep->cur_rate);
1208
		ep->pps = 1000 >> ep->datainterval;
1209
	} else {
1210
		ep->freqn = get_usb_high_speed_rate(ep->cur_rate);
1211
		ep->pps = 8000 >> ep->datainterval;
1212
1213
	}

1214
1215
1216
	ep->sample_rem = ep->cur_rate % ep->pps;
	ep->packsize[0] = ep->cur_rate / ep->pps;
	ep->packsize[1] = (ep->cur_rate + (ep->pps - 1)) / ep->pps;
1217
1218
1219
1220
1221
1222
1223
1224
1225

	/* 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:
1226
		err = data_ep_set_params(ep);
1227
1228
		break;
	case  SND_USB_ENDPOINT_TYPE_SYNC:
1229
		err = sync_ep_set_params(ep);
1230
1231
1232
1233
1234
		break;
	default:
		err = -EINVAL;
	}

1235
	usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err);
1236

1237
1238
1239
	if (err < 0)
		return err;

1240
1241
1242
	/* some unit conversions in runtime */
	ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;
	ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
1243
1244

	return 0;
1245
1246
}

1247
1248
1249
1250
1251
/*
 * snd_usb_endpoint_configure: Configure the endpoint
 *
 * This function sets up the EP to be fully usable state.
 * It's called either from hw_params or prepare callback.
1252
 * The function checks need_setup flag, and performs nothing unless needed,
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
 * so it's safe to call this multiple times.
 *
 * This returns zero if unchanged, 1 if the configuration has changed,
 * or a negative error code.
 */
int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
			       struct snd_usb_endpoint *ep)
{
	bool iface_first;
	int err = 0;

	mutex_lock(&chip->mutex);
1265
1266
	if (WARN_ON(!ep->iface_ref))
		goto unlock;
1267
1268
1269
	if (!ep->need_setup)
		goto unlock;

1270
1271
	/* If the interface has been already set up, just set EP parameters */
	if (!ep->iface_ref->need_setup) {
1272
1273
1274
1275
1276
1277
1278
1279
1280
		/* sample rate setup of UAC1 is per endpoint, and we need
		 * to update at each EP configuration
		 */
		if (ep->cur_audiofmt->protocol == UAC_VERSION_1) {
			err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt,
						       ep->cur_rate);
			if (err < 0)
				goto unlock;
		}
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
		err = snd_usb_endpoint_set_params(chip, ep);
		if (err < 0)
			goto unlock;
		goto done;
	}

	/* Need to deselect altsetting at first */
	endpoint_set_interface(chip, ep, false);

	/* Some UAC1 devices (e.g. Yamaha THR10) need the host interface
	 * to be set up before parameter setups
	 */
	iface_first = ep->cur_audiofmt->protocol == UAC_VERSION_1;
1294
1295
1296
1297
1298
	/* Workaround for Sony WALKMAN NW-A45 DAC;
	 * it requires the interface setup at first like UAC1
	 */
	if (chip->usb_id == USB_ID(0x054c, 0x0b8c))
		iface_first = true;
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319