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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 */4 5#include <linux/gfp.h>6#include <linux/init.h>7#include <linux/ratelimit.h>8#include <linux/usb.h>9#include <linux/usb/audio.h>10#include <linux/slab.h>11 12#include <sound/core.h>13#include <sound/pcm.h>14#include <sound/pcm_params.h>15 16#include "usbaudio.h"17#include "helper.h"18#include "card.h"19#include "endpoint.h"20#include "pcm.h"21#include "clock.h"22#include "quirks.h"23 24enum {25	EP_STATE_STOPPED,26	EP_STATE_RUNNING,27	EP_STATE_STOPPING,28};29 30/* interface refcounting */31struct snd_usb_iface_ref {32	unsigned char iface;33	bool need_setup;34	int opened;35	int altset;36	struct list_head list;37};38 39/* clock refcounting */40struct snd_usb_clock_ref {41	unsigned char clock;42	atomic_t locked;43	int opened;44	int rate;45	bool need_setup;46	struct list_head list;47};48 49/*50 * snd_usb_endpoint is a model that abstracts everything related to an51 * USB endpoint and its streaming.52 *53 * There are functions to activate and deactivate the streaming URBs and54 * optional callbacks to let the pcm logic handle the actual content of the55 * packets for playback and record. Thus, the bus streaming and the audio56 * handlers are fully decoupled.57 *58 * There are two different types of endpoints in audio applications.59 *60 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both61 * inbound and outbound traffic.62 *63 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and64 * expect the payload to carry Q10.14 / Q16.16 formatted sync information65 * (3 or 4 bytes).66 *67 * Each endpoint has to be configured prior to being used by calling68 * snd_usb_endpoint_set_params().69 *70 * The model incorporates a reference counting, so that multiple users71 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and72 * only the first user will effectively start the URBs, and only the last73 * one to stop it will tear the URBs down again.74 */75 76/*77 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)78 * this will overflow at approx 524 kHz79 */80static inline unsigned get_usb_full_speed_rate(unsigned int rate)81{82	return ((rate << 13) + 62) / 125;83}84 85/*86 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)87 * this will overflow at approx 4 MHz88 */89static inline unsigned get_usb_high_speed_rate(unsigned int rate)90{91	return ((rate << 10) + 62) / 125;92}93 94/*95 * release a urb data96 */97static void release_urb_ctx(struct snd_urb_ctx *u)98{99	if (u->urb && u->buffer_size)100		usb_free_coherent(u->ep->chip->dev, u->buffer_size,101				  u->urb->transfer_buffer,102				  u->urb->transfer_dma);103	usb_free_urb(u->urb);104	u->urb = NULL;105	u->buffer_size = 0;106}107 108static const char *usb_error_string(int err)109{110	switch (err) {111	case -ENODEV:112		return "no device";113	case -ENOENT:114		return "endpoint not enabled";115	case -EPIPE:116		return "endpoint stalled";117	case -ENOSPC:118		return "not enough bandwidth";119	case -ESHUTDOWN:120		return "device disabled";121	case -EHOSTUNREACH:122		return "device suspended";123	case -EINVAL:124	case -EAGAIN:125	case -EFBIG:126	case -EMSGSIZE:127		return "internal error";128	default:129		return "unknown error";130	}131}132 133static inline bool ep_state_running(struct snd_usb_endpoint *ep)134{135	return atomic_read(&ep->state) == EP_STATE_RUNNING;136}137 138static inline bool ep_state_update(struct snd_usb_endpoint *ep, int old, int new)139{140	return atomic_try_cmpxchg(&ep->state, &old, new);141}142 143/**144 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type145 *146 * @ep: The snd_usb_endpoint147 *148 * Determine whether an endpoint is driven by an implicit feedback149 * data endpoint source.150 */151int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)152{153	return  ep->implicit_fb_sync && usb_pipeout(ep->pipe);154}155 156/*157 * Return the number of samples to be sent in the next packet158 * for streaming based on information derived from sync endpoints159 *160 * This won't be used for implicit feedback which takes the packet size161 * returned from the sync source162 */163static int slave_next_packet_size(struct snd_usb_endpoint *ep,164				  unsigned int avail)165{166	unsigned long flags;167	unsigned int phase;168	int ret;169 170	if (ep->fill_max)171		return ep->maxframesize;172 173	spin_lock_irqsave(&ep->lock, flags);174	phase = (ep->phase & 0xffff) + (ep->freqm << ep->datainterval);175	ret = min(phase >> 16, ep->maxframesize);176	if (avail && ret >= avail)177		ret = -EAGAIN;178	else179		ep->phase = phase;180	spin_unlock_irqrestore(&ep->lock, flags);181 182	return ret;183}184 185/*186 * Return the number of samples to be sent in the next packet187 * for adaptive and synchronous endpoints188 */189static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail)190{191	unsigned int sample_accum;192	int ret;193 194	if (ep->fill_max)195		return ep->maxframesize;196 197	sample_accum = ep->sample_accum + ep->sample_rem;198	if (sample_accum >= ep->pps) {199		sample_accum -= ep->pps;200		ret = ep->packsize[1];201	} else {202		ret = ep->packsize[0];203	}204	if (avail && ret >= avail)205		ret = -EAGAIN;206	else207		ep->sample_accum = sample_accum;208 209	return ret;210}211 212/*213 * snd_usb_endpoint_next_packet_size: Return the number of samples to be sent214 * in the next packet215 *216 * If the size is equal or exceeds @avail, don't proceed but return -EAGAIN217 * Exception: @avail = 0 for skipping the check.218 */219int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,220				      struct snd_urb_ctx *ctx, int idx,221				      unsigned int avail)222{223	unsigned int packet;224 225	packet = ctx->packet_size[idx];226	if (packet) {227		if (avail && packet >= avail)228			return -EAGAIN;229		return packet;230	}231 232	if (ep->sync_source)233		return slave_next_packet_size(ep, avail);234	else235		return next_packet_size(ep, avail);236}237 238static void call_retire_callback(struct snd_usb_endpoint *ep,239				 struct urb *urb)240{241	struct snd_usb_substream *data_subs;242 243	data_subs = READ_ONCE(ep->data_subs);244	if (data_subs && ep->retire_data_urb)245		ep->retire_data_urb(data_subs, urb);246}247 248static void retire_outbound_urb(struct snd_usb_endpoint *ep,249				struct snd_urb_ctx *urb_ctx)250{251	call_retire_callback(ep, urb_ctx->urb);252}253 254static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,255				    struct snd_usb_endpoint *sender,256				    const struct urb *urb);257 258static void retire_inbound_urb(struct snd_usb_endpoint *ep,259			       struct snd_urb_ctx *urb_ctx)260{261	struct urb *urb = urb_ctx->urb;262	struct snd_usb_endpoint *sync_sink;263 264	if (unlikely(ep->skip_packets > 0)) {265		ep->skip_packets--;266		return;267	}268 269	sync_sink = READ_ONCE(ep->sync_sink);270	if (sync_sink)271		snd_usb_handle_sync_urb(sync_sink, ep, urb);272 273	call_retire_callback(ep, urb);274}275 276static inline bool has_tx_length_quirk(struct snd_usb_audio *chip)277{278	return chip->quirk_flags & QUIRK_FLAG_TX_LENGTH;279}280 281static void prepare_silent_urb(struct snd_usb_endpoint *ep,282			       struct snd_urb_ctx *ctx)283{284	struct urb *urb = ctx->urb;285	unsigned int offs = 0;286	unsigned int extra = 0;287	__le32 packet_length;288	int i;289 290	/* For tx_length_quirk, put packet length at start of packet */291	if (has_tx_length_quirk(ep->chip))292		extra = sizeof(packet_length);293 294	for (i = 0; i < ctx->packets; ++i) {295		unsigned int offset;296		unsigned int length;297		int counts;298 299		counts = snd_usb_endpoint_next_packet_size(ep, ctx, i, 0);300		length = counts * ep->stride; /* number of silent bytes */301		offset = offs * ep->stride + extra * i;302		urb->iso_frame_desc[i].offset = offset;303		urb->iso_frame_desc[i].length = length + extra;304		if (extra) {305			packet_length = cpu_to_le32(length);306			memcpy(urb->transfer_buffer + offset,307			       &packet_length, sizeof(packet_length));308		}309		memset(urb->transfer_buffer + offset + extra,310		       ep->silence_value, length);311		offs += counts;312	}313 314	urb->number_of_packets = ctx->packets;315	urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;316	ctx->queued = 0;317}318 319/*320 * Prepare a PLAYBACK urb for submission to the bus.321 */322static int prepare_outbound_urb(struct snd_usb_endpoint *ep,323				struct snd_urb_ctx *ctx,324				bool in_stream_lock)325{326	struct urb *urb = ctx->urb;327	unsigned char *cp = urb->transfer_buffer;328	struct snd_usb_substream *data_subs;329 330	urb->dev = ep->chip->dev; /* we need to set this at each time */331 332	switch (ep->type) {333	case SND_USB_ENDPOINT_TYPE_DATA:334		data_subs = READ_ONCE(ep->data_subs);335		if (data_subs && ep->prepare_data_urb)336			return ep->prepare_data_urb(data_subs, urb, in_stream_lock);337		/* no data provider, so send silence */338		prepare_silent_urb(ep, ctx);339		break;340 341	case SND_USB_ENDPOINT_TYPE_SYNC:342		if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {343			/*344			 * fill the length and offset of each urb descriptor.345			 * the fixed 12.13 frequency is passed as 16.16 through the pipe.346			 */347			urb->iso_frame_desc[0].length = 4;348			urb->iso_frame_desc[0].offset = 0;349			cp[0] = ep->freqn;350			cp[1] = ep->freqn >> 8;351			cp[2] = ep->freqn >> 16;352			cp[3] = ep->freqn >> 24;353		} else {354			/*355			 * fill the length and offset of each urb descriptor.356			 * the fixed 10.14 frequency is passed through the pipe.357			 */358			urb->iso_frame_desc[0].length = 3;359			urb->iso_frame_desc[0].offset = 0;360			cp[0] = ep->freqn >> 2;361			cp[1] = ep->freqn >> 10;362			cp[2] = ep->freqn >> 18;363		}364 365		break;366	}367	return 0;368}369 370/*371 * Prepare a CAPTURE or SYNC urb for submission to the bus.372 */373static int prepare_inbound_urb(struct snd_usb_endpoint *ep,374			       struct snd_urb_ctx *urb_ctx)375{376	int i, offs;377	struct urb *urb = urb_ctx->urb;378 379	urb->dev = ep->chip->dev; /* we need to set this at each time */380 381	switch (ep->type) {382	case SND_USB_ENDPOINT_TYPE_DATA:383		offs = 0;384		for (i = 0; i < urb_ctx->packets; i++) {385			urb->iso_frame_desc[i].offset = offs;386			urb->iso_frame_desc[i].length = ep->curpacksize;387			offs += ep->curpacksize;388		}389 390		urb->transfer_buffer_length = offs;391		urb->number_of_packets = urb_ctx->packets;392		break;393 394	case SND_USB_ENDPOINT_TYPE_SYNC:395		urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);396		urb->iso_frame_desc[0].offset = 0;397		break;398	}399	return 0;400}401 402/* notify an error as XRUN to the assigned PCM data substream */403static void notify_xrun(struct snd_usb_endpoint *ep)404{405	struct snd_usb_substream *data_subs;406 407	data_subs = READ_ONCE(ep->data_subs);408	if (data_subs && data_subs->pcm_substream)409		snd_pcm_stop_xrun(data_subs->pcm_substream);410}411 412static struct snd_usb_packet_info *413next_packet_fifo_enqueue(struct snd_usb_endpoint *ep)414{415	struct snd_usb_packet_info *p;416 417	p = ep->next_packet + (ep->next_packet_head + ep->next_packet_queued) %418		ARRAY_SIZE(ep->next_packet);419	ep->next_packet_queued++;420	return p;421}422 423static struct snd_usb_packet_info *424next_packet_fifo_dequeue(struct snd_usb_endpoint *ep)425{426	struct snd_usb_packet_info *p;427 428	p = ep->next_packet + ep->next_packet_head;429	ep->next_packet_head++;430	ep->next_packet_head %= ARRAY_SIZE(ep->next_packet);431	ep->next_packet_queued--;432	return p;433}434 435static void push_back_to_ready_list(struct snd_usb_endpoint *ep,436				    struct snd_urb_ctx *ctx)437{438	unsigned long flags;439 440	spin_lock_irqsave(&ep->lock, flags);441	list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);442	spin_unlock_irqrestore(&ep->lock, flags);443}444 445/*446 * Send output urbs that have been prepared previously. URBs are dequeued447 * from ep->ready_playback_urbs and in case there aren't any available448 * or there are no packets that have been prepared, this function does449 * nothing.450 *451 * The reason why the functionality of sending and preparing URBs is separated452 * is that host controllers don't guarantee the order in which they return453 * inbound and outbound packets to their submitters.454 *455 * This function is used both for implicit feedback endpoints and in low-456 * latency playback mode.457 */458int snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint *ep,459				      bool in_stream_lock)460{461	bool implicit_fb = snd_usb_endpoint_implicit_feedback_sink(ep);462 463	while (ep_state_running(ep)) {464 465		unsigned long flags;466		struct snd_usb_packet_info *packet;467		struct snd_urb_ctx *ctx = NULL;468		int err, i;469 470		spin_lock_irqsave(&ep->lock, flags);471		if ((!implicit_fb || ep->next_packet_queued > 0) &&472		    !list_empty(&ep->ready_playback_urbs)) {473			/* take URB out of FIFO */474			ctx = list_first_entry(&ep->ready_playback_urbs,475					       struct snd_urb_ctx, ready_list);476			list_del_init(&ctx->ready_list);477			if (implicit_fb)478				packet = next_packet_fifo_dequeue(ep);479		}480		spin_unlock_irqrestore(&ep->lock, flags);481 482		if (ctx == NULL)483			break;484 485		/* copy over the length information */486		if (implicit_fb) {487			for (i = 0; i < packet->packets; i++)488				ctx->packet_size[i] = packet->packet_size[i];489		}490 491		/* call the data handler to fill in playback data */492		err = prepare_outbound_urb(ep, ctx, in_stream_lock);493		/* can be stopped during prepare callback */494		if (unlikely(!ep_state_running(ep)))495			break;496		if (err < 0) {497			/* push back to ready list again for -EAGAIN */498			if (err == -EAGAIN) {499				push_back_to_ready_list(ep, ctx);500				break;501			}502 503			if (!in_stream_lock)504				notify_xrun(ep);505			return -EPIPE;506		}507 508		if (!atomic_read(&ep->chip->shutdown))509			err = usb_submit_urb(ctx->urb, GFP_ATOMIC);510		else511			err = -ENODEV;512		if (err < 0) {513			if (!atomic_read(&ep->chip->shutdown)) {514				usb_audio_err(ep->chip,515					      "Unable to submit urb #%d: %d at %s\n",516					      ctx->index, err, __func__);517				if (!in_stream_lock)518					notify_xrun(ep);519			}520			return -EPIPE;521		}522 523		set_bit(ctx->index, &ep->active_mask);524		atomic_inc(&ep->submitted_urbs);525	}526 527	return 0;528}529 530/*531 * complete callback for urbs532 */533static void snd_complete_urb(struct urb *urb)534{535	struct snd_urb_ctx *ctx = urb->context;536	struct snd_usb_endpoint *ep = ctx->ep;537	int err;538 539	if (unlikely(urb->status == -ENOENT ||		/* unlinked */540		     urb->status == -ENODEV ||		/* device removed */541		     urb->status == -ECONNRESET ||	/* unlinked */542		     urb->status == -ESHUTDOWN))	/* device disabled */543		goto exit_clear;544	/* device disconnected */545	if (unlikely(atomic_read(&ep->chip->shutdown)))546		goto exit_clear;547 548	if (unlikely(!ep_state_running(ep)))549		goto exit_clear;550 551	if (usb_pipeout(ep->pipe)) {552		retire_outbound_urb(ep, ctx);553		/* can be stopped during retire callback */554		if (unlikely(!ep_state_running(ep)))555			goto exit_clear;556 557		/* in low-latency and implicit-feedback modes, push back the558		 * URB to ready list at first, then process as much as possible559		 */560		if (ep->lowlatency_playback ||561		     snd_usb_endpoint_implicit_feedback_sink(ep)) {562			push_back_to_ready_list(ep, ctx);563			clear_bit(ctx->index, &ep->active_mask);564			snd_usb_queue_pending_output_urbs(ep, false);565			atomic_dec(&ep->submitted_urbs); /* decrement at last */566			return;567		}568 569		/* in non-lowlatency mode, no error handling for prepare */570		prepare_outbound_urb(ep, ctx, false);571		/* can be stopped during prepare callback */572		if (unlikely(!ep_state_running(ep)))573			goto exit_clear;574	} else {575		retire_inbound_urb(ep, ctx);576		/* can be stopped during retire callback */577		if (unlikely(!ep_state_running(ep)))578			goto exit_clear;579 580		prepare_inbound_urb(ep, ctx);581	}582 583	if (!atomic_read(&ep->chip->shutdown))584		err = usb_submit_urb(urb, GFP_ATOMIC);585	else586		err = -ENODEV;587	if (err == 0)588		return;589 590	if (!atomic_read(&ep->chip->shutdown)) {591		usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);592		notify_xrun(ep);593	}594 595exit_clear:596	clear_bit(ctx->index, &ep->active_mask);597	atomic_dec(&ep->submitted_urbs);598}599 600/*601 * Find or create a refcount object for the given interface602 *603 * The objects are released altogether in snd_usb_endpoint_free_all()604 */605static struct snd_usb_iface_ref *606iface_ref_find(struct snd_usb_audio *chip, int iface)607{608	struct snd_usb_iface_ref *ip;609 610	list_for_each_entry(ip, &chip->iface_ref_list, list)611		if (ip->iface == iface)612			return ip;613 614	ip = kzalloc(sizeof(*ip), GFP_KERNEL);615	if (!ip)616		return NULL;617	ip->iface = iface;618	list_add_tail(&ip->list, &chip->iface_ref_list);619	return ip;620}621 622/* Similarly, a refcount object for clock */623static struct snd_usb_clock_ref *624clock_ref_find(struct snd_usb_audio *chip, int clock)625{626	struct snd_usb_clock_ref *ref;627 628	list_for_each_entry(ref, &chip->clock_ref_list, list)629		if (ref->clock == clock)630			return ref;631 632	ref = kzalloc(sizeof(*ref), GFP_KERNEL);633	if (!ref)634		return NULL;635	ref->clock = clock;636	atomic_set(&ref->locked, 0);637	list_add_tail(&ref->list, &chip->clock_ref_list);638	return ref;639}640 641/*642 * Get the existing endpoint object corresponding EP643 * Returns NULL if not present.644 */645struct snd_usb_endpoint *646snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num)647{648	struct snd_usb_endpoint *ep;649 650	list_for_each_entry(ep, &chip->ep_list, list) {651		if (ep->ep_num == ep_num)652			return ep;653	}654 655	return NULL;656}657 658#define ep_type_name(type) \659	(type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync")660 661/**662 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip663 *664 * @chip: The chip665 * @ep_num: The number of the endpoint to use666 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC667 *668 * If the requested endpoint has not been added to the given chip before,669 * a new instance is created.670 *671 * Returns zero on success or a negative error code.672 *673 * New endpoints will be added to chip->ep_list and freed by674 * calling snd_usb_endpoint_free_all().675 *676 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that677 * bNumEndpoints > 1 beforehand.678 */679int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type)680{681	struct snd_usb_endpoint *ep;682	bool is_playback;683 684	ep = snd_usb_get_endpoint(chip, ep_num);685	if (ep)686		return 0;687 688	usb_audio_dbg(chip, "Creating new %s endpoint #%x\n",689		      ep_type_name(type),690		      ep_num);691	ep = kzalloc(sizeof(*ep), GFP_KERNEL);692	if (!ep)693		return -ENOMEM;694 695	ep->chip = chip;696	spin_lock_init(&ep->lock);697	ep->type = type;698	ep->ep_num = ep_num;699	INIT_LIST_HEAD(&ep->ready_playback_urbs);700	atomic_set(&ep->submitted_urbs, 0);701 702	is_playback = ((ep_num & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);703	ep_num &= USB_ENDPOINT_NUMBER_MASK;704	if (is_playback)705		ep->pipe = usb_sndisocpipe(chip->dev, ep_num);706	else707		ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);708 709	list_add_tail(&ep->list, &chip->ep_list);710	return 0;711}712 713/* Set up syncinterval and maxsyncsize for a sync EP */714static void endpoint_set_syncinterval(struct snd_usb_audio *chip,715				      struct snd_usb_endpoint *ep)716{717	struct usb_host_interface *alts;718	struct usb_endpoint_descriptor *desc;719 720	alts = snd_usb_get_host_interface(chip, ep->iface, ep->altsetting);721	if (!alts)722		return;723 724	desc = get_endpoint(alts, ep->ep_idx);725	if (desc->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&726	    desc->bRefresh >= 1 && desc->bRefresh <= 9)727		ep->syncinterval = desc->bRefresh;728	else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)729		ep->syncinterval = 1;730	else if (desc->bInterval >= 1 && desc->bInterval <= 16)731		ep->syncinterval = desc->bInterval - 1;732	else733		ep->syncinterval = 3;734 735	ep->syncmaxsize = le16_to_cpu(desc->wMaxPacketSize);736}737 738static bool endpoint_compatible(struct snd_usb_endpoint *ep,739				const struct audioformat *fp,740				const struct snd_pcm_hw_params *params)741{742	if (!ep->opened)743		return false;744	if (ep->cur_audiofmt != fp)745		return false;746	if (ep->cur_rate != params_rate(params) ||747	    ep->cur_format != params_format(params) ||748	    ep->cur_period_frames != params_period_size(params) ||749	    ep->cur_buffer_periods != params_periods(params))750		return false;751	return true;752}753 754/*755 * Check whether the given fp and hw params are compatible with the current756 * setup of the target EP for implicit feedback sync757 */758bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,759				 struct snd_usb_endpoint *ep,760				 const struct audioformat *fp,761				 const struct snd_pcm_hw_params *params)762{763	bool ret;764 765	mutex_lock(&chip->mutex);766	ret = endpoint_compatible(ep, fp, params);767	mutex_unlock(&chip->mutex);768	return ret;769}770 771/*772 * snd_usb_endpoint_open: Open the endpoint773 *774 * Called from hw_params to assign the endpoint to the substream.775 * It's reference-counted, and only the first opener is allowed to set up776 * arbitrary parameters.  The later opener must be compatible with the777 * former opened parameters.778 * The endpoint needs to be closed via snd_usb_endpoint_close() later.779 *780 * Note that this function doesn't configure the endpoint.  The substream781 * needs to set it up later via snd_usb_endpoint_set_params() and782 * snd_usb_endpoint_prepare().783 */784struct snd_usb_endpoint *785snd_usb_endpoint_open(struct snd_usb_audio *chip,786		      const struct audioformat *fp,787		      const struct snd_pcm_hw_params *params,788		      bool is_sync_ep,789		      bool fixed_rate)790{791	struct snd_usb_endpoint *ep;792	int ep_num = is_sync_ep ? fp->sync_ep : fp->endpoint;793 794	mutex_lock(&chip->mutex);795	ep = snd_usb_get_endpoint(chip, ep_num);796	if (!ep) {797		usb_audio_err(chip, "Cannot find EP 0x%x to open\n", ep_num);798		goto unlock;799	}800 801	if (!ep->opened) {802		if (is_sync_ep) {803			ep->iface = fp->sync_iface;804			ep->altsetting = fp->sync_altsetting;805			ep->ep_idx = fp->sync_ep_idx;806		} else {807			ep->iface = fp->iface;808			ep->altsetting = fp->altsetting;809			ep->ep_idx = fp->ep_idx;810		}811		usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",812			      ep_num, ep->iface, ep->altsetting, ep->ep_idx);813 814		ep->iface_ref = iface_ref_find(chip, ep->iface);815		if (!ep->iface_ref) {816			ep = NULL;817			goto unlock;818		}819 820		if (fp->protocol != UAC_VERSION_1) {821			ep->clock_ref = clock_ref_find(chip, fp->clock);822			if (!ep->clock_ref) {823				ep = NULL;824				goto unlock;825			}826			ep->clock_ref->opened++;827		}828 829		ep->cur_audiofmt = fp;830		ep->cur_channels = fp->channels;831		ep->cur_rate = params_rate(params);832		ep->cur_format = params_format(params);833		ep->cur_frame_bytes = snd_pcm_format_physical_width(ep->cur_format) *834			ep->cur_channels / 8;835		ep->cur_period_frames = params_period_size(params);836		ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes;837		ep->cur_buffer_periods = params_periods(params);838 839		if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC)840			endpoint_set_syncinterval(chip, ep);841 842		ep->implicit_fb_sync = fp->implicit_fb;843		ep->need_setup = true;844		ep->need_prepare = true;845		ep->fixed_rate = fixed_rate;846 847		usb_audio_dbg(chip, "  channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n",848			      ep->cur_channels, ep->cur_rate,849			      snd_pcm_format_name(ep->cur_format),850			      ep->cur_period_bytes, ep->cur_buffer_periods,851			      ep->implicit_fb_sync);852 853	} else {854		if (WARN_ON(!ep->iface_ref)) {855			ep = NULL;856			goto unlock;857		}858 859		if (!endpoint_compatible(ep, fp, params)) {860			usb_audio_err(chip, "Incompatible EP setup for 0x%x\n",861				      ep_num);862			ep = NULL;863			goto unlock;864		}865 866		usb_audio_dbg(chip, "Reopened EP 0x%x (count %d)\n",867			      ep_num, ep->opened);868	}869 870	if (!ep->iface_ref->opened++)871		ep->iface_ref->need_setup = true;872 873	ep->opened++;874 875 unlock:876	mutex_unlock(&chip->mutex);877	return ep;878}879 880/*881 * snd_usb_endpoint_set_sync: Link data and sync endpoints882 *883 * Pass NULL to sync_ep to unlink again884 */885void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,886			       struct snd_usb_endpoint *data_ep,887			       struct snd_usb_endpoint *sync_ep)888{889	data_ep->sync_source = sync_ep;890}891 892/*893 * Set data endpoint callbacks and the assigned data stream894 *895 * Called at PCM trigger and cleanups.896 * Pass NULL to deactivate each callback.897 */898void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,899				   int (*prepare)(struct snd_usb_substream *subs,900						  struct urb *urb,901						  bool in_stream_lock),902				   void (*retire)(struct snd_usb_substream *subs,903						  struct urb *urb),904				   struct snd_usb_substream *data_subs)905{906	ep->prepare_data_urb = prepare;907	ep->retire_data_urb = retire;908	if (data_subs)909		ep->lowlatency_playback = data_subs->lowlatency_playback;910	else911		ep->lowlatency_playback = false;912	WRITE_ONCE(ep->data_subs, data_subs);913}914 915static int endpoint_set_interface(struct snd_usb_audio *chip,916				  struct snd_usb_endpoint *ep,917				  bool set)918{919	int altset = set ? ep->altsetting : 0;920	int err;921 922	if (ep->iface_ref->altset == altset)923		return 0;924	/* already disconnected? */925	if (unlikely(atomic_read(&chip->shutdown)))926		return -ENODEV;927 928	usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",929		      ep->iface, altset, ep->ep_num);930	err = usb_set_interface(chip->dev, ep->iface, altset);931	if (err < 0) {932		usb_audio_err_ratelimited(933			chip, "%d:%d: usb_set_interface failed (%d)\n",934			ep->iface, altset, err);935		return err;936	}937 938	if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)939		msleep(50);940	ep->iface_ref->altset = altset;941	return 0;942}943 944/*945 * snd_usb_endpoint_close: Close the endpoint946 *947 * Unreference the already opened endpoint via snd_usb_endpoint_open().948 */949void snd_usb_endpoint_close(struct snd_usb_audio *chip,950			    struct snd_usb_endpoint *ep)951{952	mutex_lock(&chip->mutex);953	usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",954		      ep->ep_num, ep->opened);955 956	if (!--ep->iface_ref->opened &&957		!(chip->quirk_flags & QUIRK_FLAG_IFACE_SKIP_CLOSE))958		endpoint_set_interface(chip, ep, false);959 960	if (!--ep->opened) {961		if (ep->clock_ref) {962			if (!--ep->clock_ref->opened)963				ep->clock_ref->rate = 0;964		}965		ep->iface = 0;966		ep->altsetting = 0;967		ep->cur_audiofmt = NULL;968		ep->cur_rate = 0;969		ep->iface_ref = NULL;970		ep->clock_ref = NULL;971		usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num);972	}973	mutex_unlock(&chip->mutex);974}975 976/* Prepare for suspening EP, called from the main suspend handler */977void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep)978{979	ep->need_prepare = true;980	if (ep->iface_ref)981		ep->iface_ref->need_setup = true;982	if (ep->clock_ref)983		ep->clock_ref->rate = 0;984}985 986/*987 *  wait until all urbs are processed.988 */989static int wait_clear_urbs(struct snd_usb_endpoint *ep)990{991	unsigned long end_time = jiffies + msecs_to_jiffies(1000);992	int alive;993 994	if (atomic_read(&ep->state) != EP_STATE_STOPPING)995		return 0;996 997	do {998		alive = atomic_read(&ep->submitted_urbs);999		if (!alive)1000			break;1001 1002		schedule_timeout_uninterruptible(1);1003	} while (time_before(jiffies, end_time));1004 1005	if (alive)1006		usb_audio_err(ep->chip,1007			"timeout: still %d active urbs on EP #%x\n",1008			alive, ep->ep_num);1009 1010	if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {1011		ep->sync_sink = NULL;1012		snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);1013	}1014 1015	return 0;1016}1017 1018/* sync the pending stop operation;1019 * this function itself doesn't trigger the stop operation1020 */1021void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)1022{1023	if (ep)1024		wait_clear_urbs(ep);1025}1026 1027/*1028 * Stop active urbs1029 *1030 * This function moves the EP to STOPPING state if it's being RUNNING.1031 */1032static int stop_urbs(struct snd_usb_endpoint *ep, bool force, bool keep_pending)1033{1034	unsigned int i;1035	unsigned long flags;1036 1037	if (!force && atomic_read(&ep->running))1038		return -EBUSY;1039 1040	if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))1041		return 0;1042 1043	spin_lock_irqsave(&ep->lock, flags);1044	INIT_LIST_HEAD(&ep->ready_playback_urbs);1045	ep->next_packet_head = 0;1046	ep->next_packet_queued = 0;1047	spin_unlock_irqrestore(&ep->lock, flags);1048 1049	if (keep_pending)1050		return 0;1051 1052	for (i = 0; i < ep->nurbs; i++) {1053		if (test_bit(i, &ep->active_mask)) {1054			if (!test_and_set_bit(i, &ep->unlink_mask)) {1055				struct urb *u = ep->urb[i].urb;1056				usb_unlink_urb(u);1057			}1058		}1059	}1060 1061	return 0;1062}1063 1064/*1065 * release an endpoint's urbs1066 */1067static int release_urbs(struct snd_usb_endpoint *ep, bool force)1068{1069	int i, err;1070 1071	/* route incoming urbs to nirvana */1072	snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);1073 1074	/* stop and unlink urbs */1075	err = stop_urbs(ep, force, false);1076	if (err)1077		return err;1078 1079	wait_clear_urbs(ep);1080 1081	for (i = 0; i < ep->nurbs; i++)1082		release_urb_ctx(&ep->urb[i]);1083 1084	usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,1085			  ep->syncbuf, ep->sync_dma);1086 1087	ep->syncbuf = NULL;1088	ep->nurbs = 0;1089	return 0;1090}1091 1092/*1093 * configure a data endpoint1094 */1095static int data_ep_set_params(struct snd_usb_endpoint *ep)1096{1097	struct snd_usb_audio *chip = ep->chip;1098	unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;1099	unsigned int max_packs_per_period, urbs_per_period, urb_packs;1100	unsigned int max_urbs, i;1101	const struct audioformat *fmt = ep->cur_audiofmt;1102	int frame_bits = ep->cur_frame_bytes * 8;1103	int tx_length_quirk = (has_tx_length_quirk(chip) &&1104			       usb_pipeout(ep->pipe));1105 1106	usb_audio_dbg(chip, "Setting params for data EP 0x%x, pipe 0x%x\n",1107		      ep->ep_num, ep->pipe);1108 1109	if (ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {1110		/*1111		 * When operating in DSD DOP mode, the size of a sample frame1112		 * in hardware differs from the actual physical format width1113		 * because we need to make room for the DOP markers.1114		 */1115		frame_bits += ep->cur_channels << 3;1116	}1117 1118	ep->datainterval = fmt->datainterval;1119	ep->stride = frame_bits >> 3;1120 1121	switch (ep->cur_format) {1122	case SNDRV_PCM_FORMAT_U8:1123		ep->silence_value = 0x80;1124		break;1125	case SNDRV_PCM_FORMAT_DSD_U8:1126	case SNDRV_PCM_FORMAT_DSD_U16_LE:1127	case SNDRV_PCM_FORMAT_DSD_U32_LE:1128	case SNDRV_PCM_FORMAT_DSD_U16_BE:1129	case SNDRV_PCM_FORMAT_DSD_U32_BE:1130		ep->silence_value = 0x69;1131		break;1132	default:1133		ep->silence_value = 0;1134	}1135 1136	/* assume max. frequency is 50% higher than nominal */1137	ep->freqmax = ep->freqn + (ep->freqn >> 1);1138	/* Round up freqmax to nearest integer in order to calculate maximum1139	 * packet size, which must represent a whole number of frames.1140	 * This is accomplished by adding 0x0.ffff before converting the1141	 * Q16.16 format into integer.1142	 * In order to accurately calculate the maximum packet size when1143	 * the data interval is more than 1 (i.e. ep->datainterval > 0),1144	 * multiply by the data interval prior to rounding. For instance,1145	 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)1146	 * frames with a data interval of 1, but 11 (10.25) frames with a1147	 * data interval of 2.1148	 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the1149	 * maximum datainterval value of 3, at USB full speed, higher for1150	 * USB high speed, noting that ep->freqmax is in units of1151	 * frames per packet in Q16.16 format.)1152	 */1153	maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *1154			 (frame_bits >> 3);1155	if (tx_length_quirk)1156		maxsize += sizeof(__le32); /* Space for length descriptor */1157	/* but wMaxPacketSize might reduce this */1158	if (ep->maxpacksize && ep->maxpacksize < maxsize) {1159		/* whatever fits into a max. size packet */1160		unsigned int data_maxsize = maxsize = ep->maxpacksize;1161 1162		if (tx_length_quirk)1163			/* Need to remove the length descriptor to calc freq */1164			data_maxsize -= sizeof(__le32);1165		ep->freqmax = (data_maxsize / (frame_bits >> 3))1166				<< (16 - ep->datainterval);1167	}1168 1169	if (ep->fill_max)1170		ep->curpacksize = ep->maxpacksize;1171	else1172		ep->curpacksize = maxsize;1173 1174	if (snd_usb_get_speed(chip->dev) != USB_SPEED_FULL) {1175		packs_per_ms = 8 >> ep->datainterval;1176		max_packs_per_urb = MAX_PACKS_HS;1177	} else {1178		packs_per_ms = 1;1179		max_packs_per_urb = MAX_PACKS;1180	}1181	if (ep->sync_source && !ep->implicit_fb_sync)1182		max_packs_per_urb = min(max_packs_per_urb,1183					1U << ep->sync_source->syncinterval);1184	max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);1185 1186	/*1187	 * Capture endpoints need to use small URBs because there's no way1188	 * to tell in advance where the next period will end, and we don't1189	 * want the next URB to complete much after the period ends.1190	 *1191	 * Playback endpoints with implicit sync much use the same parameters1192	 * as their corresponding capture endpoint.1193	 */1194	if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) {1195 1196		/* make capture URBs <= 1 ms and smaller than a period */1197		urb_packs = min(max_packs_per_urb, packs_per_ms);1198		while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes)1199			urb_packs >>= 1;1200		ep->nurbs = MAX_URBS;1201 1202	/*1203	 * Playback endpoints without implicit sync are adjusted so that1204	 * a period fits as evenly as possible in the smallest number of1205	 * URBs.  The total number of URBs is adjusted to the size of the1206	 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.1207	 */1208	} else {1209		/* determine how small a packet can be */1210		minsize = (ep->freqn >> (16 - ep->datainterval)) *1211				(frame_bits >> 3);1212		/* with sync from device, assume it can be 12% lower */1213		if (ep->sync_source)1214			minsize -= minsize >> 3;1215		minsize = max(minsize, 1u);1216 1217		/* how many packets will contain an entire ALSA period? */1218		max_packs_per_period = DIV_ROUND_UP(ep->cur_period_bytes, minsize);1219 1220		/* how many URBs will contain a period? */1221		urbs_per_period = DIV_ROUND_UP(max_packs_per_period,1222				max_packs_per_urb);1223		/* how many packets are needed in each URB? */1224		urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);1225 1226		/* limit the number of frames in a single URB */1227		ep->max_urb_frames = DIV_ROUND_UP(ep->cur_period_frames,1228						  urbs_per_period);1229 1230		/* try to use enough URBs to contain an entire ALSA buffer */1231		max_urbs = min((unsigned) MAX_URBS,1232				MAX_QUEUE * packs_per_ms / urb_packs);1233		ep->nurbs = min(max_urbs, urbs_per_period * ep->cur_buffer_periods);1234	}1235 1236	/* allocate and initialize data urbs */1237	for (i = 0; i < ep->nurbs; i++) {1238		struct snd_urb_ctx *u = &ep->urb[i];1239		u->index = i;1240		u->ep = ep;1241		u->packets = urb_packs;1242		u->buffer_size = maxsize * u->packets;1243 1244		if (fmt->fmt_type == UAC_FORMAT_TYPE_II)1245			u->packets++; /* for transfer delimiter */1246		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);1247		if (!u->urb)1248			goto out_of_memory;1249 1250		u->urb->transfer_buffer =1251			usb_alloc_coherent(chip->dev, u->buffer_size,1252					   GFP_KERNEL, &u->urb->transfer_dma);1253		if (!u->urb->transfer_buffer)1254			goto out_of_memory;1255		u->urb->pipe = ep->pipe;1256		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;1257		u->urb->interval = 1 << ep->datainterval;1258		u->urb->context = u;1259		u->urb->complete = snd_complete_urb;1260		INIT_LIST_HEAD(&u->ready_list);1261	}1262 1263	return 0;1264 1265out_of_memory:1266	release_urbs(ep, false);1267	return -ENOMEM;1268}1269 1270/*1271 * configure a sync endpoint1272 */1273static int sync_ep_set_params(struct snd_usb_endpoint *ep)1274{1275	struct snd_usb_audio *chip = ep->chip;1276	int i;1277 1278	usb_audio_dbg(chip, "Setting params for sync EP 0x%x, pipe 0x%x\n",1279		      ep->ep_num, ep->pipe);1280 1281	ep->syncbuf = usb_alloc_coherent(chip->dev, SYNC_URBS * 4,1282					 GFP_KERNEL, &ep->sync_dma);1283	if (!ep->syncbuf)1284		return -ENOMEM;1285 1286	ep->nurbs = SYNC_URBS;1287	for (i = 0; i < SYNC_URBS; i++) {1288		struct snd_urb_ctx *u = &ep->urb[i];1289		u->index = i;1290		u->ep = ep;1291		u->packets = 1;1292		u->urb = usb_alloc_urb(1, GFP_KERNEL);1293		if (!u->urb)1294			goto out_of_memory;1295		u->urb->transfer_buffer = ep->syncbuf + i * 4;1296		u->urb->transfer_dma = ep->sync_dma + i * 4;1297		u->urb->transfer_buffer_length = 4;1298		u->urb->pipe = ep->pipe;1299		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;1300		u->urb->number_of_packets = 1;1301		u->urb->interval = 1 << ep->syncinterval;1302		u->urb->context = u;1303		u->urb->complete = snd_complete_urb;1304	}1305 1306	return 0;1307 1308out_of_memory:1309	release_urbs(ep, false);1310	return -ENOMEM;1311}1312 1313/* update the rate of the referred clock; return the actual rate */1314static int update_clock_ref_rate(struct snd_usb_audio *chip,1315				 struct snd_usb_endpoint *ep)1316{1317	struct snd_usb_clock_ref *clock = ep->clock_ref;1318	int rate = ep->cur_rate;1319 1320	if (!clock || clock->rate == rate)1321		return rate;1322	if (clock->rate) {1323		if (atomic_read(&clock->locked))1324			return clock->rate;1325		if (clock->rate != rate) {1326			usb_audio_err(chip, "Mismatched sample rate %d vs %d for EP 0x%x\n",1327				      clock->rate, rate, ep->ep_num);1328			return clock->rate;1329		}1330	}1331	clock->rate = rate;1332	clock->need_setup = true;1333	return rate;1334}1335 1336/*1337 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint1338 *1339 * It's called either from hw_params callback.1340 * Determine the number of URBs to be used on this endpoint.1341 * An endpoint must be configured before it can be started.1342 * An endpoint that is already running can not be reconfigured.1343 */1344int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,1345				struct snd_usb_endpoint *ep)1346{1347	const struct audioformat *fmt = ep->cur_audiofmt;1348	int err = 0;1349 1350	mutex_lock(&chip->mutex);1351	if (!ep->need_setup)1352		goto unlock;1353 1354	/* release old buffers, if any */1355	err = release_urbs(ep, false);1356	if (err < 0)1357		goto unlock;1358 1359	ep->datainterval = fmt->datainterval;1360	ep->maxpacksize = fmt->maxpacksize;1361	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);1362 1363	if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) {1364		ep->freqn = get_usb_full_speed_rate(ep->cur_rate);1365		ep->pps = 1000 >> ep->datainterval;1366	} else {1367		ep->freqn = get_usb_high_speed_rate(ep->cur_rate);1368		ep->pps = 8000 >> ep->datainterval;1369	}1370 1371	ep->sample_rem = ep->cur_rate % ep->pps;1372	ep->packsize[0] = ep->cur_rate / ep->pps;1373	ep->packsize[1] = (ep->cur_rate + (ep->pps - 1)) / ep->pps;1374 1375	/* calculate the frequency in 16.16 format */1376	ep->freqm = ep->freqn;1377	ep->freqshift = INT_MIN;1378 1379	ep->phase = 0;1380 1381	switch (ep->type) {1382	case  SND_USB_ENDPOINT_TYPE_DATA:1383		err = data_ep_set_params(ep);1384		break;1385	case  SND_USB_ENDPOINT_TYPE_SYNC:1386		err = sync_ep_set_params(ep);1387		break;1388	default:1389		err = -EINVAL;1390	}1391 1392	usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err);1393 1394	if (err < 0)1395		goto unlock;1396 1397	/* some unit conversions in runtime */1398	ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;1399	ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;1400 1401	err = update_clock_ref_rate(chip, ep);1402	if (err >= 0) {1403		ep->need_setup = false;1404		err = 0;1405	}1406 1407 unlock:1408	mutex_unlock(&chip->mutex);1409	return err;1410}1411 1412static int init_sample_rate(struct snd_usb_audio *chip,1413			    struct snd_usb_endpoint *ep)1414{1415	struct snd_usb_clock_ref *clock = ep->clock_ref;1416	int rate, err;1417 1418	rate = update_clock_ref_rate(chip, ep);1419	if (rate < 0)1420		return rate;1421	if (clock && !clock->need_setup)1422		return 0;1423 1424	if (!ep->fixed_rate) {1425		err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, rate);1426		if (err < 0) {1427			if (clock)1428				clock->rate = 0; /* reset rate */1429			return err;1430		}1431	}1432 1433	if (clock)1434		clock->need_setup = false;1435	return 0;1436}1437 1438/*1439 * snd_usb_endpoint_prepare: Prepare the endpoint1440 *1441 * This function sets up the EP to be fully usable state.1442 * It's called either from prepare callback.1443 * The function checks need_setup flag, and performs nothing unless needed,1444 * so it's safe to call this multiple times.1445 *1446 * This returns zero if unchanged, 1 if the configuration has changed,1447 * or a negative error code.1448 */1449int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,1450			     struct snd_usb_endpoint *ep)1451{1452	bool iface_first;1453	int err = 0;1454 1455	mutex_lock(&chip->mutex);1456	if (WARN_ON(!ep->iface_ref))1457		goto unlock;1458	if (!ep->need_prepare)1459		goto unlock;1460 1461	/* If the interface has been already set up, just set EP parameters */1462	if (!ep->iface_ref->need_setup) {1463		/* sample rate setup of UAC1 is per endpoint, and we need1464		 * to update at each EP configuration1465		 */1466		if (ep->cur_audiofmt->protocol == UAC_VERSION_1) {1467			err = init_sample_rate(chip, ep);1468			if (err < 0)1469				goto unlock;1470		}1471		goto done;1472	}1473 1474	/* Need to deselect altsetting at first */1475	endpoint_set_interface(chip, ep, false);1476 1477	/* Some UAC1 devices (e.g. Yamaha THR10) need the host interface1478	 * to be set up before parameter setups1479	 */1480	iface_first = ep->cur_audiofmt->protocol == UAC_VERSION_1;1481	/* Workaround for devices that require the interface setup at first like UAC1 */1482	if (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST)1483		iface_first = true;1484	if (iface_first) {1485		err = endpoint_set_interface(chip, ep, true);1486		if (err < 0)1487			goto unlock;1488	}1489 1490	err = snd_usb_init_pitch(chip, ep->cur_audiofmt);1491	if (err < 0)1492		goto unlock;1493 1494	err = init_sample_rate(chip, ep);1495	if (err < 0)1496		goto unlock;1497 1498	err = snd_usb_select_mode_quirk(chip, ep->cur_audiofmt);1499	if (err < 0)1500		goto unlock;1501 1502	/* for UAC2/3, enable the interface altset here at last */1503	if (!iface_first) {1504		err = endpoint_set_interface(chip, ep, true);1505		if (err < 0)1506			goto unlock;1507	}1508 1509	ep->iface_ref->need_setup = false;1510 1511 done:1512	ep->need_prepare = false;1513	err = 1;1514 1515unlock:1516	mutex_unlock(&chip->mutex);1517	return err;1518}1519 1520/* get the current rate set to the given clock by any endpoint */1521int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock)1522{1523	struct snd_usb_clock_ref *ref;1524	int rate = 0;1525 1526	if (!clock)1527		return 0;1528	mutex_lock(&chip->mutex);1529	list_for_each_entry(ref, &chip->clock_ref_list, list) {1530		if (ref->clock == clock) {1531			rate = ref->rate;1532			break;1533		}1534	}1535	mutex_unlock(&chip->mutex);1536	return rate;1537}1538 1539/**1540 * snd_usb_endpoint_start: start an snd_usb_endpoint1541 *1542 * @ep: the endpoint to start1543 *1544 * A call to this function will increment the running count of the endpoint.1545 * In case it is not already running, the URBs for this endpoint will be1546 * submitted. Otherwise, this function does nothing.1547 *1548 * Must be balanced to calls of snd_usb_endpoint_stop().1549 *1550 * Returns an error if the URB submission failed, 0 in all other cases.1551 */1552int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)1553{1554	bool is_playback = usb_pipeout(ep->pipe);1555	int err;1556	unsigned int i;1557 1558	if (atomic_read(&ep->chip->shutdown))1559		return -EBADFD;1560 1561	if (ep->sync_source)1562		WRITE_ONCE(ep->sync_source->sync_sink, ep);1563 1564	usb_audio_dbg(ep->chip, "Starting %s EP 0x%x (running %d)\n",1565		      ep_type_name(ep->type), ep->ep_num,1566		      atomic_read(&ep->running));1567 1568	/* already running? */1569	if (atomic_inc_return(&ep->running) != 1)1570		return 0;1571 1572	if (ep->clock_ref)1573		atomic_inc(&ep->clock_ref->locked);1574 1575	ep->active_mask = 0;1576	ep->unlink_mask = 0;1577	ep->phase = 0;1578	ep->sample_accum = 0;1579 1580	snd_usb_endpoint_start_quirk(ep);1581 1582	/*1583	 * If this endpoint has a data endpoint as implicit feedback source,1584	 * don't start the urbs here. Instead, mark them all as available,1585	 * wait for the record urbs to return and queue the playback urbs1586	 * from that context.1587	 */1588 1589	if (!ep_state_update(ep, EP_STATE_STOPPED, EP_STATE_RUNNING))1590		goto __error;1591 1592	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&1593	    !(ep->chip->quirk_flags & QUIRK_FLAG_PLAYBACK_FIRST)) {1594		usb_audio_dbg(ep->chip, "No URB submission due to implicit fb sync\n");1595		i = 0;1596		goto fill_rest;1597	}1598 1599	for (i = 0; i < ep->nurbs; i++) {1600		struct urb *urb = ep->urb[i].urb;1601 1602		if (snd_BUG_ON(!urb))1603			goto __error;1604 1605		if (is_playback)1606			err = prepare_outbound_urb(ep, urb->context, true);1607		else1608			err = prepare_inbound_urb(ep, urb->context);1609		if (err < 0) {1610			/* stop filling at applptr */1611			if (err == -EAGAIN)1612				break;1613			usb_audio_dbg(ep->chip,1614				      "EP 0x%x: failed to prepare urb: %d\n",1615				      ep->ep_num, err);1616			goto __error;1617		}1618 1619		if (!atomic_read(&ep->chip->shutdown))1620			err = usb_submit_urb(urb, GFP_ATOMIC);1621		else1622			err = -ENODEV;1623		if (err < 0) {1624			if (!atomic_read(&ep->chip->shutdown))1625				usb_audio_err(ep->chip,1626					      "cannot submit urb %d, error %d: %s\n",1627					      i, err, usb_error_string(err));1628			goto __error;1629		}1630		set_bit(i, &ep->active_mask);1631		atomic_inc(&ep->submitted_urbs);1632	}1633 1634	if (!i) {1635		usb_audio_dbg(ep->chip, "XRUN at starting EP 0x%x\n",1636			      ep->ep_num);1637		goto __error;1638	}1639 1640	usb_audio_dbg(ep->chip, "%d URBs submitted for EP 0x%x\n",1641		      i, ep->ep_num);1642 1643 fill_rest:1644	/* put the remaining URBs to ready list */1645	if (is_playback) {1646		for (; i < ep->nurbs; i++)1647			push_back_to_ready_list(ep, ep->urb + i);1648	}1649 1650	return 0;1651 1652__error:1653	snd_usb_endpoint_stop(ep, false);1654	return -EPIPE;1655}1656 1657/**1658 * snd_usb_endpoint_stop: stop an snd_usb_endpoint1659 *1660 * @ep: the endpoint to stop (may be NULL)1661 * @keep_pending: keep in-flight URBs1662 *1663 * A call to this function will decrement the running count of the endpoint.1664 * In case the last user has requested the endpoint stop, the URBs will1665 * actually be deactivated.1666 *1667 * Must be balanced to calls of snd_usb_endpoint_start().1668 *1669 * The caller needs to synchronize the pending stop operation via1670 * snd_usb_endpoint_sync_pending_stop().1671 */1672void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool keep_pending)1673{1674	if (!ep)1675		return;1676 1677	usb_audio_dbg(ep->chip, "Stopping %s EP 0x%x (running %d)\n",1678		      ep_type_name(ep->type), ep->ep_num,1679		      atomic_read(&ep->running));1680 1681	if (snd_BUG_ON(!atomic_read(&ep->running)))1682		return;1683 1684	if (!atomic_dec_return(&ep->running)) {1685		if (ep->sync_source)1686			WRITE_ONCE(ep->sync_source->sync_sink, NULL);1687		stop_urbs(ep, false, keep_pending);1688		if (ep->clock_ref)1689			atomic_dec(&ep->clock_ref->locked);1690 1691		if (ep->chip->quirk_flags & QUIRK_FLAG_FORCE_IFACE_RESET &&1692		    usb_pipeout(ep->pipe)) {1693			ep->need_prepare = true;1694			if (ep->iface_ref)1695				ep->iface_ref->need_setup = true;1696		}1697	}1698}1699 1700/**1701 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint1702 *1703 * @ep: the endpoint to release1704 *1705 * This function does not care for the endpoint's running count but will tear1706 * down all the streaming URBs immediately.1707 */1708void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)1709{1710	release_urbs(ep, true);1711}1712 1713/**1714 * snd_usb_endpoint_free_all: Free the resources of an snd_usb_endpoint1715 * @chip: The chip1716 *1717 * This free all endpoints and those resources1718 */1719void snd_usb_endpoint_free_all(struct snd_usb_audio *chip)1720{1721	struct snd_usb_endpoint *ep, *en;1722	struct snd_usb_iface_ref *ip, *in;1723	struct snd_usb_clock_ref *cp, *cn;1724 1725	list_for_each_entry_safe(ep, en, &chip->ep_list, list)1726		kfree(ep);1727 1728	list_for_each_entry_safe(ip, in, &chip->iface_ref_list, list)1729		kfree(ip);1730 1731	list_for_each_entry_safe(cp, cn, &chip->clock_ref_list, list)1732		kfree(cp);1733}1734 1735/*1736 * snd_usb_handle_sync_urb: parse an USB sync packet1737 *1738 * @ep: the endpoint to handle the packet1739 * @sender: the sending endpoint1740 * @urb: the received packet1741 *1742 * This function is called from the context of an endpoint that received1743 * the packet and is used to let another endpoint object handle the payload.1744 */1745static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,1746				    struct snd_usb_endpoint *sender,1747				    const struct urb *urb)1748{1749	int shift;1750	unsigned int f;1751	unsigned long flags;1752 1753	snd_BUG_ON(ep == sender);1754 1755	/*1756	 * In case the endpoint is operating in implicit feedback mode, prepare1757	 * a new outbound URB that has the same layout as the received packet1758	 * and add it to the list of pending urbs. queue_pending_output_urbs()1759	 * will take care of them later.1760	 */1761	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&1762	    atomic_read(&ep->running)) {1763 1764		/* implicit feedback case */1765		int i, bytes = 0;1766		struct snd_urb_ctx *in_ctx;1767		struct snd_usb_packet_info *out_packet;1768 1769		in_ctx = urb->context;1770 1771		/* Count overall packet size */1772		for (i = 0; i < in_ctx->packets; i++)1773			if (urb->iso_frame_desc[i].status == 0)1774				bytes += urb->iso_frame_desc[i].actual_length;1775 1776		/*1777		 * skip empty packets. At least M-Audio's Fast Track Ultra stops1778		 * streaming once it received a 0-byte OUT URB1779		 */1780		if (bytes == 0)1781			return;1782 1783		spin_lock_irqsave(&ep->lock, flags);1784		if (ep->next_packet_queued >= ARRAY_SIZE(ep->next_packet)) {1785			spin_unlock_irqrestore(&ep->lock, flags);1786			usb_audio_err(ep->chip,1787				      "next package FIFO overflow EP 0x%x\n",1788				      ep->ep_num);1789			notify_xrun(ep);1790			return;1791		}1792 1793		out_packet = next_packet_fifo_enqueue(ep);1794 1795		/*1796		 * Iterate through the inbound packet and prepare the lengths1797		 * for the output packet. The OUT packet we are about to send1798		 * will have the same amount of payload bytes per stride as the1799		 * IN packet we just received. Since the actual size is scaled1800		 * by the stride, use the sender stride to calculate the length1801		 * in case the number of channels differ between the implicitly1802		 * fed-back endpoint and the synchronizing endpoint.1803		 */1804 1805		out_packet->packets = in_ctx->packets;1806		for (i = 0; i < in_ctx->packets; i++) {1807			if (urb->iso_frame_desc[i].status == 0)1808				out_packet->packet_size[i] =1809					urb->iso_frame_desc[i].actual_length / sender->stride;1810			else1811				out_packet->packet_size[i] = 0;1812		}1813 1814		spin_unlock_irqrestore(&ep->lock, flags);1815		snd_usb_queue_pending_output_urbs(ep, false);1816 1817		return;1818	}1819 1820	/*1821	 * process after playback sync complete1822	 *1823	 * Full speed devices report feedback values in 10.14 format as samples1824	 * per frame, high speed devices in 16.16 format as samples per1825	 * microframe.1826	 *1827	 * Because the Audio Class 1 spec was written before USB 2.0, many high1828	 * speed devices use a wrong interpretation, some others use an1829	 * entirely different format.1830	 *1831	 * Therefore, we cannot predict what format any particular device uses1832	 * and must detect it automatically.1833	 */1834 1835	if (urb->iso_frame_desc[0].status != 0 ||1836	    urb->iso_frame_desc[0].actual_length < 3)1837		return;1838 1839	f = le32_to_cpup(urb->transfer_buffer);1840	if (urb->iso_frame_desc[0].actual_length == 3)1841		f &= 0x00ffffff;1842	else1843		f &= 0x0fffffff;1844 1845	if (f == 0)1846		return;1847 1848	if (unlikely(sender->tenor_fb_quirk)) {1849		/*1850		 * Devices based on Tenor 8802 chipsets (TEAC UD-H011851		 * and others) sometimes change the feedback value1852		 * by +/- 0x1.0000.1853		 */1854		if (f < ep->freqn - 0x8000)1855			f += 0xf000;1856		else if (f > ep->freqn + 0x8000)1857			f -= 0xf000;1858	} else if (unlikely(ep->freqshift == INT_MIN)) {1859		/*1860		 * The first time we see a feedback value, determine its format1861		 * by shifting it left or right until it matches the nominal1862		 * frequency value.  This assumes that the feedback does not1863		 * differ from the nominal value more than +50% or -25%.1864		 */1865		shift = 0;1866		while (f < ep->freqn - ep->freqn / 4) {1867			f <<= 1;1868			shift++;1869		}1870		while (f > ep->freqn + ep->freqn / 2) {1871			f >>= 1;1872			shift--;1873		}1874		ep->freqshift = shift;1875	} else if (ep->freqshift >= 0)1876		f <<= ep->freqshift;1877	else1878		f >>= -ep->freqshift;1879 1880	if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {1881		/*1882		 * If the frequency looks valid, set it.1883		 * This value is referred to in prepare_playback_urb().1884		 */1885		spin_lock_irqsave(&ep->lock, flags);1886		ep->freqm = f;1887		spin_unlock_irqrestore(&ep->lock, flags);1888	} else {1889		/*1890		 * Out of range; maybe the shift value is wrong.1891		 * Reset it so that we autodetect again the next time.1892		 */1893		ep->freqshift = INT_MIN;1894	}1895}1896 1897