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endpoint.c
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endpoint.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
*/
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/ratelimit.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include "usbaudio.h"
#include "helper.h"
#include "card.h"
#include "endpoint.h"
#include "pcm.h"
#include "clock.h"
#include "quirks.h"
enum {
EP_STATE_STOPPED,
EP_STATE_RUNNING,
EP_STATE_STOPPING,
};
/* interface refcounting */
struct snd_usb_iface_ref {
unsigned char iface;
bool need_setup;
int opened;
struct list_head list;
};
/*
* 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
* optional callbacks to let the pcm logic handle the actual content of the
* packets for playback and record. Thus, the bus streaming and the audio
* handlers are fully decoupled.
*
* There are two different types of endpoints in audio applications.
*
* SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
* inbound and outbound traffic.
*
* 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).
*
* Each endpoint has to be configured prior to being used by calling
* snd_usb_endpoint_set_params().
*
* 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
* one to stop it will tear the URBs down again.
*/
/*
* 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)
{
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;
}
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";
}
}
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;
}
/**
* snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
*
* @ep: The snd_usb_endpoint
*
* Determine whether an endpoint is driven by an implicit feedback
* data endpoint source.
*/
int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
{
return ep->implicit_fb_sync && usb_pipeout(ep->pipe);
}
/*
* Return the number of samples to be sent in the next packet
* for streaming based on information derived from sync endpoints
*
* This won't be used for implicit feedback which takes the packet size
* returned from the sync source
*/
static int slave_next_packet_size(struct snd_usb_endpoint *ep,
unsigned int avail)
{
unsigned long flags;
unsigned int phase;
int ret;
if (ep->fill_max)
return ep->maxframesize;
spin_lock_irqsave(&ep->lock, flags);
phase = (ep->phase & 0xffff) + (ep->freqm << ep->datainterval);
ret = min(phase >> 16, ep->maxframesize);
if (avail && ret >= avail)
ret = -EAGAIN;
else
ep->phase = phase;
spin_unlock_irqrestore(&ep->lock, flags);
return ret;
}
/*
* Return the number of samples to be sent in the next packet
* for adaptive and synchronous endpoints
*/
static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail)
{
unsigned int sample_accum;
int ret;
if (ep->fill_max)
return ep->maxframesize;
sample_accum = ep->sample_accum + ep->sample_rem;
if (sample_accum >= ep->pps) {
sample_accum -= ep->pps;
ret = ep->packsize[1];
} else {
ret = ep->packsize[0];
}
if (avail && ret >= avail)
ret = -EAGAIN;
else
ep->sample_accum = sample_accum;
return ret;
}
/*
* snd_usb_endpoint_next_packet_size: Return the number of samples to be sent
* in the next packet
*
* If the size is equal or exceeds @avail, don't proceed but return -EAGAIN
* Exception: @avail = 0 for skipping the check.
*/
int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *ctx, int idx,
unsigned int avail)
{
unsigned int packet;
packet = ctx->packet_size[idx];
if (packet) {
if (avail && packet >= avail)
return -EAGAIN;
return packet;
}
if (ep->sync_source)
return slave_next_packet_size(ep, avail);
else
return next_packet_size(ep, avail);
}
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);
}
static void retire_outbound_urb(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *urb_ctx)
{
call_retire_callback(ep, urb_ctx->urb);
}
static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
struct snd_usb_endpoint *sender,
const struct urb *urb);
static void retire_inbound_urb(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *urb_ctx)
{
struct urb *urb = urb_ctx->urb;
struct snd_usb_endpoint *sync_sink;
if (unlikely(ep->skip_packets > 0)) {
ep->skip_packets--;
return;
}
sync_sink = READ_ONCE(ep->sync_sink);
if (sync_sink)
snd_usb_handle_sync_urb(sync_sink, ep, urb);
call_retire_callback(ep, urb);
}
static inline bool has_tx_length_quirk(struct snd_usb_audio *chip)
{
return chip->quirk_flags & QUIRK_FLAG_TX_LENGTH;
}
static void prepare_silent_urb(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *ctx)
{
struct urb *urb = ctx->urb;
unsigned int offs = 0;
unsigned int extra = 0;
__le32 packet_length;
int i;
/* For tx_length_quirk, put packet length at start of packet */
if (has_tx_length_quirk(ep->chip))
extra = sizeof(packet_length);
for (i = 0; i < ctx->packets; ++i) {
unsigned int offset;
unsigned int length;
int counts;
counts = snd_usb_endpoint_next_packet_size(ep, ctx, i, 0);
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);
offs += counts;
}
urb->number_of_packets = ctx->packets;
urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
ctx->queued = 0;
}
/*
* Prepare a PLAYBACK urb for submission to the bus.
*/
static int prepare_outbound_urb(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *ctx,
bool in_stream_lock)
{
struct urb *urb = ctx->urb;
unsigned char *cp = urb->transfer_buffer;
struct snd_usb_substream *data_subs;
urb->dev = ep->chip->dev; /* we need to set this at each time */
switch (ep->type) {
case SND_USB_ENDPOINT_TYPE_DATA:
data_subs = READ_ONCE(ep->data_subs);
if (data_subs && ep->prepare_data_urb)
return ep->prepare_data_urb(data_subs, urb, in_stream_lock);
/* no data provider, so send silence */
prepare_silent_urb(ep, ctx);
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;
}
return 0;
}
/*
* Prepare a CAPTURE or SYNC urb for submission to the bus.
*/
static int 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;
}
return 0;
}
/* 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;
}
static void push_back_to_ready_list(struct snd_usb_endpoint *ep,
struct snd_urb_ctx *ctx)
{
unsigned long flags;
spin_lock_irqsave(&ep->lock, flags);
list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
spin_unlock_irqrestore(&ep->lock, flags);
}
/*
* Send output urbs that have been prepared previously. URBs are dequeued
* from ep->ready_playback_urbs and in case there aren't any available
* or there are no packets that have been prepared, this function does
* nothing.
*
* 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.
*
* This function is used both for implicit feedback endpoints and in low-
* latency playback mode.
*/
void snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint *ep,
bool in_stream_lock)
{
bool implicit_fb = snd_usb_endpoint_implicit_feedback_sink(ep);
while (ep_state_running(ep)) {
unsigned long flags;
struct snd_usb_packet_info *packet;
struct snd_urb_ctx *ctx = NULL;
int err, i;
spin_lock_irqsave(&ep->lock, flags);
if ((!implicit_fb || ep->next_packet_queued > 0) &&
!list_empty(&ep->ready_playback_urbs)) {
/* take URB out of FIFO */
ctx = list_first_entry(&ep->ready_playback_urbs,
struct snd_urb_ctx, ready_list);
list_del_init(&ctx->ready_list);
if (implicit_fb)
packet = next_packet_fifo_dequeue(ep);
}
spin_unlock_irqrestore(&ep->lock, flags);
if (ctx == NULL)
return;
/* copy over the length information */
if (implicit_fb) {
for (i = 0; i < packet->packets; i++)
ctx->packet_size[i] = packet->packet_size[i];
}
/* call the data handler to fill in playback data */
err = prepare_outbound_urb(ep, ctx, in_stream_lock);
/* can be stopped during prepare callback */
if (unlikely(!ep_state_running(ep)))
break;
if (err < 0) {
/* push back to ready list again for -EAGAIN */
if (err == -EAGAIN)
push_back_to_ready_list(ep, ctx);
else
notify_xrun(ep);
return;
}
err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
if (err < 0) {
usb_audio_err(ep->chip,
"Unable to submit urb #%d: %d at %s\n",
ctx->index, err, __func__);
notify_xrun(ep);
return;
}
set_bit(ctx->index, &ep->active_mask);
atomic_inc(&ep->submitted_urbs);
}
}
/*
* complete callback for urbs
*/
static void snd_complete_urb(struct urb *urb)
{
struct snd_urb_ctx *ctx = urb->context;
struct snd_usb_endpoint *ep = ctx->ep;
int err;
if (unlikely(urb->status == -ENOENT || /* unlinked */
urb->status == -ENODEV || /* device removed */
urb->status == -ECONNRESET || /* unlinked */
urb->status == -ESHUTDOWN)) /* device disabled */
goto exit_clear;
/* device disconnected */
if (unlikely(atomic_read(&ep->chip->shutdown)))
goto exit_clear;
if (unlikely(!ep_state_running(ep)))
goto exit_clear;
if (usb_pipeout(ep->pipe)) {
retire_outbound_urb(ep, ctx);
/* can be stopped during retire callback */
if (unlikely(!ep_state_running(ep)))
goto exit_clear;
/* in low-latency and implicit-feedback modes, push back the
* URB to ready list at first, then process as much as possible
*/
if (ep->lowlatency_playback ||
snd_usb_endpoint_implicit_feedback_sink(ep)) {
push_back_to_ready_list(ep, ctx);
clear_bit(ctx->index, &ep->active_mask);
snd_usb_queue_pending_output_urbs(ep, false);
atomic_dec(&ep->submitted_urbs); /* decrement at last */
return;
}
/* in non-lowlatency mode, no error handling for prepare */
prepare_outbound_urb(ep, ctx, false);
/* can be stopped during prepare callback */
if (unlikely(!ep_state_running(ep)))
goto exit_clear;
} else {
retire_inbound_urb(ep, ctx);
/* can be stopped during retire callback */
if (unlikely(!ep_state_running(ep)))
goto exit_clear;
prepare_inbound_urb(ep, ctx);
}
err = usb_submit_urb(urb, GFP_ATOMIC);
if (err == 0)
return;
usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
notify_xrun(ep);
exit_clear:
clear_bit(ctx->index, &ep->active_mask);
atomic_dec(&ep->submitted_urbs);
}
/*
* 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;
}
/*
* Get the existing endpoint object corresponding EP
* Returns NULL if not present.
*/
struct snd_usb_endpoint *
snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num)
{
struct snd_usb_endpoint *ep;
list_for_each_entry(ep, &chip->ep_list, list) {
if (ep->ep_num == ep_num)
return ep;
}
return NULL;
}
#define ep_type_name(type) \
(type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync")
/**
* snd_usb_add_endpoint: Add an endpoint to an USB audio chip
*
* @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,
* a new instance is created.
*
* Returns zero on success or a negative error code.
*
* New endpoints will be added to chip->ep_list and freed by
* calling snd_usb_endpoint_free_all().
*
* For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
* bNumEndpoints > 1 beforehand.
*/
int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type)
{
struct snd_usb_endpoint *ep;
bool is_playback;
ep = snd_usb_get_endpoint(chip, ep_num);
if (ep)
return 0;
usb_audio_dbg(chip, "Creating new %s endpoint #%x\n",
ep_type_name(type),
ep_num);
ep = kzalloc(sizeof(*ep), GFP_KERNEL);
if (!ep)
return -ENOMEM;
ep->chip = chip;
spin_lock_init(&ep->lock);
ep->type = type;
ep->ep_num = ep_num;
INIT_LIST_HEAD(&ep->ready_playback_urbs);
atomic_set(&ep->submitted_urbs, 0);
is_playback = ((ep_num & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);
ep_num &= USB_ENDPOINT_NUMBER_MASK;
if (is_playback)
ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
else
ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
list_add_tail(&ep->list, &chip->ep_list);
return 0;
}
/* Set up syncinterval and maxsyncsize for a sync EP */
static void endpoint_set_syncinterval(struct snd_usb_audio *chip,
struct snd_usb_endpoint *ep)
{
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 compatible 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,
const struct audioformat *fp,
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;
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;
}
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 = fp->ep_idx;
}
usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",
ep_num, ep->iface, ep->altsetting, ep->ep_idx);
ep->iface_ref = iface_ref_find(chip, ep->iface);
if (!ep->iface_ref) {
ep = NULL;
goto unlock;
}
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);
ep->cur_clock = fp->clock;
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 {
if (WARN_ON(!ep->iface_ref)) {
ep = NULL;
goto unlock;
}
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);
}
if (!ep->iface_ref->opened++)
ep->iface_ref->need_setup = true;
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)
{
data_ep->sync_source = sync_ep;
}
/*
* 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,
int (*prepare)(struct snd_usb_substream *subs,
struct urb *urb,
bool in_stream_lock),
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;
if (data_subs)
ep->lowlatency_playback = data_subs->lowlatency_playback;
else
ep->lowlatency_playback = false;
WRITE_ONCE(ep->data_subs, data_subs);
}
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;
}
if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
msleep(50);
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);
if (!--ep->iface_ref->opened)
endpoint_set_interface(chip, ep, false);
if (!--ep->opened) {
ep->iface = 0;
ep->altsetting = 0;
ep->cur_audiofmt = NULL;
ep->cur_rate = 0;
ep->cur_clock = 0;
ep->iface_ref = NULL;
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;
if (ep->iface_ref)
ep->iface_ref->need_setup = true;
}
/*
* 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;
if (atomic_read(&ep->state) != EP_STATE_STOPPING)
return 0;
do {
alive = atomic_read(&ep->submitted_urbs);
if (!alive)
break;
schedule_timeout_uninterruptible(1);
} while (time_before(jiffies, end_time));
if (alive)
usb_audio_err(ep->chip,
"timeout: still %d active urbs on EP #%x\n",
alive, ep->ep_num);
if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {
ep->sync_sink = NULL;
snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
}
return 0;
}
/* sync the pending stop operation;
* this function itself doesn't trigger the stop operation
*/
void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
{
if (ep)
wait_clear_urbs(ep);
}
/*
* Stop active urbs
*
* This function moves the EP to STOPPING state if it's being RUNNING.
*/
static int stop_urbs(struct snd_usb_endpoint *ep, bool force, bool keep_pending)
{
unsigned int i;
unsigned long flags;
if (!force && atomic_read(&ep->running))
return -EBUSY;
if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))
return 0;
spin_lock_irqsave(&ep->lock, flags);
INIT_LIST_HEAD(&ep->ready_playback_urbs);
ep->next_packet_head = 0;
ep->next_packet_queued = 0;
spin_unlock_irqrestore(&ep->lock, flags);
if (keep_pending)
return 0;
for (i = 0; i < ep->nurbs; i++) {
if (test_bit(i, &ep->active_mask)) {
if (!test_and_set_bit(i, &ep->unlink_mask)) {
struct urb *u = ep->urb[i].urb;
usb_unlink_urb(u);
}
}
}
return 0;
}
/*
* release an endpoint's urbs
*/
static int release_urbs(struct snd_usb_endpoint *ep, bool force)
{
int i, err;
/* route incoming urbs to nirvana */
snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
/* stop and unlink urbs */