endpoint.c 42.3 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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#define EP_FLAG_RUNNING		1
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#define EP_FLAG_STOPPING	2
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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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/**
 * 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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}

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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)
{
	while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {

		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(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
		goto exit_clear;

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	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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			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 */
		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
			goto exit_clear;
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	} 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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	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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	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;
}

/*
 * Check whether the given fp and hw params are compatbile with the current
 * 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,
664
		      const struct audioformat *fp,
665
666
667
668
669
		      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;
670

671
672
673
674
675
	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;
676
	}
677
678
679
680
681
682
683
684
685
686
687
688
689
690

	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;
			ep->ep_idx = 0;
		}
		usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",
			      ep_num, ep->iface, ep->altsetting, ep->ep_idx);

691
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693
694
695
696
		ep->iface_ref = iface_ref_find(chip, ep->iface);
		if (!ep->iface_ref) {
			ep = NULL;
			goto unlock;
		}

697
698
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701
702
703
704
705
706
707
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709
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711
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713
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715
716
717
718
719
		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 {
720
721
722
723
724
		if (WARN_ON(!ep->iface_ref)) {
			ep = NULL;
			goto unlock;
		}

725
726
727
728
729
730
731
732
733
734
735
		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);
	}

736
737
738
	if (!ep->iface_ref->opened++)
		ep->iface_ref->need_setup = true;

739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
	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)
{
755
	data_ep->sync_source = sync_ep;
756
757
}

758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
/*
 * 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);
}

776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
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);
807
808

	if (!--ep->iface_ref->opened)
809
		endpoint_set_interface(chip, ep, false);
810
811

	if (!--ep->opened) {
812
		ep->iface = 0;
813
814
815
		ep->altsetting = 0;
		ep->cur_audiofmt = NULL;
		ep->cur_rate = 0;
816
		ep->iface_ref = NULL;
817
818
819
820
821
822
823
824
825
		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;
826
827
	if (ep->iface_ref)
		ep->iface_ref->need_setup = true;
828
829
}

830
831
832
833
834
835
836
837
/*
 *  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;

838
839
840
	if (!test_bit(EP_FLAG_STOPPING, &ep->flags))
		return 0;

841
	do {
842
		alive = bitmap_weight(&ep->active_mask, ep->nurbs);
843
844
845
846
847
848
849
		if (!alive)
			break;

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

	if (alive)
850
851
852
		usb_audio_err(ep->chip,
			"timeout: still %d active urbs on EP #%x\n",
			alive, ep->ep_num);
853
	clear_bit(EP_FLAG_STOPPING, &ep->flags);
854

855
	ep->sync_sink = NULL;
856
	snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
857

858
859
860
	return 0;
}

861
862
863
864
865
/* 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)
{
866
	if (ep)
867
868
869
		wait_clear_urbs(ep);
}

870
/*
871
872
873
874
 * Stop and unlink active urbs.
 *
 * This function checks and clears EP_FLAG_RUNNING state.
 * When @wait_sync is set, it waits until all pending URBs are killed.
875
 */
876
877
static int stop_and_unlink_urbs(struct snd_usb_endpoint *ep, bool force,
				bool wait_sync)
878
879
880
{
	unsigned int i;

881
	if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
882
883
		return -EBADFD;

884
885
886
887
888
	if (atomic_read(&ep->running))
		return -EBUSY;

	if (!test_and_clear_bit(EP_FLAG_RUNNING, &ep->flags))
		goto out;
889

890
	set_bit(EP_FLAG_STOPPING, &ep->flags);
891
	INIT_LIST_HEAD(&ep->ready_playback_urbs);
892
893
	ep->next_packet_head = 0;
	ep->next_packet_queued = 0;
894
895
896
897
898

	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;
899
				usb_unlink_urb(u);
900
901
902
903
			}
		}
	}

904
905
906
 out:
	if (wait_sync)
		return wait_clear_urbs(ep);
907
908
909
910
911
912
913
914
915
916
917
	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 */
918
	snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
919
920

	/* stop urbs */
921
	stop_and_unlink_urbs(ep, force, true);
922
923
924
925

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

926
927
	usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
			  ep->syncbuf, ep->sync_dma);
928
929
930
931
932

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

933
934
935
/*
 * configure a data endpoint
 */
936
static int data_ep_set_params(struct snd_usb_endpoint *ep)
937
{
938
	struct snd_usb_audio *chip = ep->chip;
939
940
941
	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;
942
943
944
	const struct audioformat *fmt = ep->cur_audiofmt;
	int frame_bits = ep->cur_frame_bytes * 8;
	int tx_length_quirk = (chip->tx_length_quirk &&
945
			       usb_pipeout(ep->pipe));
946

947
948
949
950
	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) {
951
952
953
954
955
		/*
		 * 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.
		 */
956
		frame_bits += ep->cur_channels << 3;
957
958
	}

959
960
	ep->datainterval = fmt->datainterval;
	ep->stride = frame_bits >> 3;
961

962
	switch (ep->cur_format) {
963
964
965
966
967
968
969
970
971
972
973
974
975
	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;
	}
976

977
978
	/* assume max. frequency is 50% higher than nominal */
	ep->freqmax = ep->freqn + (ep->freqn >> 1);
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
	/* 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);
996
997
	if (tx_length_quirk)
		maxsize += sizeof(__le32); /* Space for length descriptor */
998
999
	/* but wMaxPacketSize might reduce this */
	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
1000
		/* whatever fits into a max. size packet */
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