/* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #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 "quirks.h" #define EP_FLAG_ACTIVATED 0 #define EP_FLAG_RUNNING 1 #define EP_FLAG_STOPPING 2 /* * 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"; } } /** * 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->sync_master && ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA && ep->type == SND_USB_ENDPOINT_TYPE_DATA && usb_pipeout(ep->pipe); } /* * For streaming based on information derived from sync endpoints, * prepare_outbound_urb_sizes() will call next_packet_size() to * determine the number of samples to be sent in the next packet. * * For implicit feedback, next_packet_size() is unused. */ int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep) { unsigned long flags; int ret; if (ep->fill_max) return ep->maxframesize; spin_lock_irqsave(&ep->lock, flags); ep->phase = (ep->phase & 0xffff) + (ep->freqm << ep->datainterval); ret = min(ep->phase >> 16, ep->maxframesize); spin_unlock_irqrestore(&ep->lock, flags); return ret; } static void retire_outbound_urb(struct snd_usb_endpoint *ep, struct snd_urb_ctx *urb_ctx) { if (ep->retire_data_urb) ep->retire_data_urb(ep->data_subs, urb_ctx->urb); } static void retire_inbound_urb(struct snd_usb_endpoint *ep, struct snd_urb_ctx *urb_ctx) { struct urb *urb = urb_ctx->urb; if (unlikely(ep->skip_packets > 0)) { ep->skip_packets--; return; } if (ep->sync_slave) snd_usb_handle_sync_urb(ep->sync_slave, ep, urb); if (ep->retire_data_urb) ep->retire_data_urb(ep->data_subs, urb); } /* * Prepare a PLAYBACK urb for submission to the bus. */ static void prepare_outbound_urb(struct snd_usb_endpoint *ep, struct snd_urb_ctx *ctx) { int i; struct urb *urb = ctx->urb; unsigned char *cp = urb->transfer_buffer; urb->dev = ep->chip->dev; /* we need to set this at each time */ switch (ep->type) { case SND_USB_ENDPOINT_TYPE_DATA: if (ep->prepare_data_urb) { ep->prepare_data_urb(ep->data_subs, urb); } else { /* no data provider, so send silence */ unsigned int offs = 0; for (i = 0; i < ctx->packets; ++i) { int counts; if (ctx->packet_size[i]) counts = ctx->packet_size[i]; else counts = snd_usb_endpoint_next_packet_size(ep); urb->iso_frame_desc[i].offset = offs * ep->stride; urb->iso_frame_desc[i].length = counts * ep->stride; offs += counts; } urb->number_of_packets = ctx->packets; urb->transfer_buffer_length = offs * ep->stride; memset(urb->transfer_buffer, ep->silence_value, offs * ep->stride); } break; case SND_USB_ENDPOINT_TYPE_SYNC: if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) { /* * fill the length and offset of each urb descriptor. * the fixed 12.13 frequency is passed as 16.16 through the pipe. */ urb->iso_frame_desc[0].length = 4; urb->iso_frame_desc[0].offset = 0; cp[0] = ep->freqn; cp[1] = ep->freqn >> 8; cp[2] = ep->freqn >> 16; cp[3] = ep->freqn >> 24; } else { /* * fill the length and offset of each urb descriptor. * the fixed 10.14 frequency is passed through the pipe. */ urb->iso_frame_desc[0].length = 3; urb->iso_frame_desc[0].offset = 0; cp[0] = ep->freqn >> 2; cp[1] = ep->freqn >> 10; cp[2] = ep->freqn >> 18; } break; } } /* * Prepare a CAPTURE or SYNC urb for submission to the bus. */ static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep, struct snd_urb_ctx *urb_ctx) { int i, offs; struct urb *urb = urb_ctx->urb; urb->dev = ep->chip->dev; /* we need to set this at each time */ switch (ep->type) { case SND_USB_ENDPOINT_TYPE_DATA: offs = 0; for (i = 0; i < urb_ctx->packets; i++) { urb->iso_frame_desc[i].offset = offs; urb->iso_frame_desc[i].length = ep->curpacksize; offs += ep->curpacksize; } urb->transfer_buffer_length = offs; urb->number_of_packets = urb_ctx->packets; break; case SND_USB_ENDPOINT_TYPE_SYNC: urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize); urb->iso_frame_desc[0].offset = 0; break; } } /* * Send output urbs that have been prepared previously. URBs are dequeued * from ep->ready_playback_urbs and in case there there aren't any available * or there are no packets that have been prepared, this function does * nothing. * * 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 only used for implicit feedback endpoints. For endpoints * driven by dedicated sync endpoints, URBs are immediately re-submitted * from their completion handler. */ static void queue_pending_output_urbs(struct snd_usb_endpoint *ep) { while (test_bit(EP_FLAG_RUNNING, &ep->flags)) { unsigned long flags; struct snd_usb_packet_info *uninitialized_var(packet); struct snd_urb_ctx *ctx = NULL; struct urb *urb; int err, i; spin_lock_irqsave(&ep->lock, flags); if (ep->next_packet_read_pos != ep->next_packet_write_pos) { packet = ep->next_packet + ep->next_packet_read_pos; ep->next_packet_read_pos++; ep->next_packet_read_pos %= MAX_URBS; /* take URB out of FIFO */ if (!list_empty(&ep->ready_playback_urbs)) ctx = list_first_entry(&ep->ready_playback_urbs, struct snd_urb_ctx, ready_list); } spin_unlock_irqrestore(&ep->lock, flags); if (ctx == NULL) return; list_del_init(&ctx->ready_list); urb = ctx->urb; /* copy over the length information */ for (i = 0; i < packet->packets; i++) ctx->packet_size[i] = packet->packet_size[i]; /* call the data handler to fill in playback data */ prepare_outbound_urb(ep, ctx); err = usb_submit_urb(ctx->urb, GFP_ATOMIC); if (err < 0) snd_printk(KERN_ERR "Unable to submit urb #%d: %d (urb %p)\n", ctx->index, err, ctx->urb); else set_bit(ctx->index, &ep->active_mask); } } /* * complete callback for urbs */ static void snd_complete_urb(struct urb *urb) { struct snd_urb_ctx *ctx = urb->context; struct snd_usb_endpoint *ep = ctx->ep; int err; if (unlikely(urb->status == -ENOENT || /* unlinked */ urb->status == -ENODEV || /* device removed */ urb->status == -ECONNRESET || /* unlinked */ urb->status == -ESHUTDOWN || /* device disabled */ ep->chip->shutdown)) /* device disconnected */ goto exit_clear; if (usb_pipeout(ep->pipe)) { retire_outbound_urb(ep, ctx); /* can be stopped during retire callback */ if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) goto exit_clear; if (snd_usb_endpoint_implicit_feedback_sink(ep)) { unsigned long flags; spin_lock_irqsave(&ep->lock, flags); list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); spin_unlock_irqrestore(&ep->lock, flags); queue_pending_output_urbs(ep); goto exit_clear; } prepare_outbound_urb(ep, ctx); } else { retire_inbound_urb(ep, ctx); /* can be stopped during retire callback */ if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) goto exit_clear; prepare_inbound_urb(ep, ctx); } err = usb_submit_urb(urb, GFP_ATOMIC); if (err == 0) return; snd_printk(KERN_ERR "cannot submit urb (err = %d)\n", err); //snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN); exit_clear: clear_bit(ctx->index, &ep->active_mask); } /** * snd_usb_add_endpoint: Add an endpoint to an USB audio chip * * @chip: The chip * @alts: The USB host interface * @ep_num: The number of the endpoint to use * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC * * If the requested endpoint has not been added to the given chip before, * a new instance is created. Otherwise, a pointer to the previoulsy * created instance is returned. In case of any error, NULL is returned. * * New endpoints will be added to chip->ep_list and must be freed by * calling snd_usb_endpoint_free(). */ struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip, struct usb_host_interface *alts, int ep_num, int direction, int type) { struct snd_usb_endpoint *ep; int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK; if (WARN_ON(!alts)) return NULL; mutex_lock(&chip->mutex); list_for_each_entry(ep, &chip->ep_list, list) { if (ep->ep_num == ep_num && ep->iface == alts->desc.bInterfaceNumber && ep->alt_idx == alts->desc.bAlternateSetting) { snd_printdd(KERN_DEBUG "Re-using EP %x in iface %d,%d @%p\n", ep_num, ep->iface, ep->alt_idx, ep); goto __exit_unlock; } } snd_printdd(KERN_DEBUG "Creating new %s %s endpoint #%x\n", is_playback ? "playback" : "capture", type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync", ep_num); ep = kzalloc(sizeof(*ep), GFP_KERNEL); if (!ep) goto __exit_unlock; ep->chip = chip; spin_lock_init(&ep->lock); ep->type = type; ep->ep_num = ep_num; ep->iface = alts->desc.bInterfaceNumber; ep->alt_idx = alts->desc.bAlternateSetting; INIT_LIST_HEAD(&ep->ready_playback_urbs); ep_num &= USB_ENDPOINT_NUMBER_MASK; if (is_playback) ep->pipe = usb_sndisocpipe(chip->dev, ep_num); else ep->pipe = usb_rcvisocpipe(chip->dev, ep_num); if (type == SND_USB_ENDPOINT_TYPE_SYNC) { if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE && get_endpoint(alts, 1)->bRefresh >= 1 && get_endpoint(alts, 1)->bRefresh <= 9) ep->syncinterval = get_endpoint(alts, 1)->bRefresh; else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) ep->syncinterval = 1; else if (get_endpoint(alts, 1)->bInterval >= 1 && get_endpoint(alts, 1)->bInterval <= 16) ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1; else ep->syncinterval = 3; ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize); } list_add_tail(&ep->list, &chip->ep_list); __exit_unlock: mutex_unlock(&chip->mutex); return ep; } /* * wait until all urbs are processed. */ static int wait_clear_urbs(struct snd_usb_endpoint *ep) { unsigned long end_time = jiffies + msecs_to_jiffies(1000); int alive; do { alive = bitmap_weight(&ep->active_mask, ep->nurbs); if (!alive) break; schedule_timeout_uninterruptible(1); } while (time_before(jiffies, end_time)); if (alive) snd_printk(KERN_ERR "timeout: still %d active urbs on EP #%x\n", alive, ep->ep_num); clear_bit(EP_FLAG_STOPPING, &ep->flags); 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 && test_bit(EP_FLAG_STOPPING, &ep->flags)) wait_clear_urbs(ep); } /* * unlink active urbs. */ static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force) { unsigned int i; if (!force && ep->chip->shutdown) /* to be sure... */ return -EBADFD; clear_bit(EP_FLAG_RUNNING, &ep->flags); INIT_LIST_HEAD(&ep->ready_playback_urbs); ep->next_packet_read_pos = 0; ep->next_packet_write_pos = 0; for (i = 0; i < ep->nurbs; i++) { if (test_bit(i, &ep->active_mask)) { if (!test_and_set_bit(i, &ep->unlink_mask)) { struct urb *u = ep->urb[i].urb; usb_unlink_urb(u); } } } return 0; } /* * release an endpoint's urbs */ static void release_urbs(struct snd_usb_endpoint *ep, int force) { int i; /* route incoming urbs to nirvana */ ep->retire_data_urb = NULL; ep->prepare_data_urb = NULL; /* stop urbs */ deactivate_urbs(ep, force); wait_clear_urbs(ep); for (i = 0; i < ep->nurbs; i++) release_urb_ctx(&ep->urb[i]); if (ep->syncbuf) usb_free_coherent(ep->chip->dev, SYNC_URBS * 4, ep->syncbuf, ep->sync_dma); ep->syncbuf = NULL; ep->nurbs = 0; } /* * configure a data endpoint */ static int data_ep_set_params(struct snd_usb_endpoint *ep, snd_pcm_format_t pcm_format, unsigned int channels, unsigned int period_bytes, struct audioformat *fmt, struct snd_usb_endpoint *sync_ep) { unsigned int maxsize, i, urb_packs, total_packs, packs_per_ms; int is_playback = usb_pipeout(ep->pipe); int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels; if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) { /* * When operating in DSD DOP mode, the size of a sample frame * in hardware differs from the actual physical format width * because we need to make room for the DOP markers. */ frame_bits += channels << 3; } ep->datainterval = fmt->datainterval; ep->stride = frame_bits >> 3; ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0; /* assume max. frequency is 25% higher than nominal */ ep->freqmax = ep->freqn + (ep->freqn >> 2); maxsize = ((ep->freqmax + 0xffff) * (frame_bits >> 3)) >> (16 - ep->datainterval); /* but wMaxPacketSize might reduce this */ if (ep->maxpacksize && ep->maxpacksize < maxsize) { /* whatever fits into a max. size packet */ maxsize = ep->maxpacksize; ep->freqmax = (maxsize / (frame_bits >> 3)) << (16 - ep->datainterval); } if (ep->fill_max) ep->curpacksize = ep->maxpacksize; else ep->curpacksize = maxsize; if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) packs_per_ms = 8 >> ep->datainterval; else packs_per_ms = 1; if (is_playback && !snd_usb_endpoint_implicit_feedback_sink(ep)) { urb_packs = max(ep->chip->nrpacks, 1); urb_packs = min(urb_packs, (unsigned int) MAX_PACKS); } else { urb_packs = 1; } urb_packs *= packs_per_ms; if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep)) urb_packs = min(urb_packs, 1U << sync_ep->syncinterval); /* decide how many packets to be used */ if (is_playback && !snd_usb_endpoint_implicit_feedback_sink(ep)) { unsigned int minsize, maxpacks; /* determine how small a packet can be */ minsize = (ep->freqn >> (16 - ep->datainterval)) * (frame_bits >> 3); /* with sync from device, assume it can be 12% lower */ if (sync_ep) minsize -= minsize >> 3; minsize = max(minsize, 1u); total_packs = (period_bytes + minsize - 1) / minsize; /* we need at least two URBs for queueing */ if (total_packs < 2) { total_packs = 2; } else { /* and we don't want too long a queue either */ maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2); total_packs = min(total_packs, maxpacks); } } else { while (urb_packs > 1 && urb_packs * maxsize >= period_bytes) urb_packs >>= 1; total_packs = MAX_URBS * urb_packs; } ep->nurbs = (total_packs + urb_packs - 1) / urb_packs; if (ep->nurbs > MAX_URBS) { /* too much... */ ep->nurbs = MAX_URBS; total_packs = MAX_URBS * urb_packs; } else if (ep->nurbs < 2) { /* too little - we need at least two packets * to ensure contiguous playback/capture */ ep->nurbs = 2; } /* allocate and initialize data urbs */ for (i = 0; i < ep->nurbs; i++) { struct snd_urb_ctx *u = &ep->urb[i]; u->index = i; u->ep = ep; u->packets = (i + 1) * total_packs / ep->nurbs - i * total_packs / ep->nurbs; u->buffer_size = maxsize * u->packets; if (fmt->fmt_type == UAC_FORMAT_TYPE_II) u->packets++; /* for transfer delimiter */ u->urb = usb_alloc_urb(u->packets, GFP_KERNEL); if (!u->urb) goto out_of_memory; u->urb->transfer_buffer = usb_alloc_coherent(ep->chip->dev, u->buffer_size, GFP_KERNEL, &u->urb->transfer_dma); if (!u->urb->transfer_buffer) goto out_of_memory; u->urb->pipe = ep->pipe; u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; u->urb->interval = 1 << ep->datainterval; u->urb->context = u; u->urb->complete = snd_complete_urb; INIT_LIST_HEAD(&u->ready_list); } return 0; out_of_memory: release_urbs(ep, 0); return -ENOMEM; } /* * configure a sync endpoint */ static int sync_ep_set_params(struct snd_usb_endpoint *ep, struct audioformat *fmt) { int i; ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4, GFP_KERNEL, &ep->sync_dma); if (!ep->syncbuf) return -ENOMEM; for (i = 0; i < SYNC_URBS; i++) { struct snd_urb_ctx *u = &ep->urb[i]; u->index = i; u->ep = ep; u->packets = 1; u->urb = usb_alloc_urb(1, GFP_KERNEL); if (!u->urb) goto out_of_memory; u->urb->transfer_buffer = ep->syncbuf + i * 4; u->urb->transfer_dma = ep->sync_dma + i * 4; u->urb->transfer_buffer_length = 4; u->urb->pipe = ep->pipe; u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; u->urb->number_of_packets = 1; u->urb->interval = 1 << ep->syncinterval; u->urb->context = u; u->urb->complete = snd_complete_urb; } ep->nurbs = SYNC_URBS; return 0; out_of_memory: release_urbs(ep, 0); return -ENOMEM; } /** * snd_usb_endpoint_set_params: configure an snd_usb_endpoint * * @ep: the snd_usb_endpoint to configure * @pcm_format: the audio fomat. * @channels: the number of audio channels. * @period_bytes: the number of bytes in one alsa period. * @rate: the frame rate. * @fmt: the USB audio format information * @sync_ep: the sync endpoint to use, if any * * Determine the number of URBs to be used on this endpoint. * An endpoint must be configured before it can be started. * An endpoint that is already running can not be reconfigured. */ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep, snd_pcm_format_t pcm_format, unsigned int channels, unsigned int period_bytes, unsigned int rate, struct audioformat *fmt, struct snd_usb_endpoint *sync_ep) { int err; if (ep->use_count != 0) { snd_printk(KERN_WARNING "Unable to change format on ep #%x: already in use\n", ep->ep_num); return -EBUSY; } /* release old buffers, if any */ release_urbs(ep, 0); ep->datainterval = fmt->datainterval; ep->maxpacksize = fmt->maxpacksize; ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX); if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL) ep->freqn = get_usb_full_speed_rate(rate); else ep->freqn = get_usb_high_speed_rate(rate); /* calculate the frequency in 16.16 format */ ep->freqm = ep->freqn; ep->freqshift = INT_MIN; ep->phase = 0; switch (ep->type) { case SND_USB_ENDPOINT_TYPE_DATA: err = data_ep_set_params(ep, pcm_format, channels, period_bytes, fmt, sync_ep); break; case SND_USB_ENDPOINT_TYPE_SYNC: err = sync_ep_set_params(ep, fmt); break; default: err = -EINVAL; } snd_printdd(KERN_DEBUG "Setting params for ep #%x (type %d, %d urbs), ret=%d\n", ep->ep_num, ep->type, ep->nurbs, err); return err; } /** * snd_usb_endpoint_start: start an snd_usb_endpoint * * @ep: the endpoint to start * @can_sleep: flag indicating whether the operation is executed in * non-atomic context * * A call to this function will increment the use count of the endpoint. * In case it is not already running, the URBs for this endpoint will be * submitted. Otherwise, this function does nothing. * * Must be balanced to calls of snd_usb_endpoint_stop(). * * Returns an error if the URB submission failed, 0 in all other cases. */ int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep) { int err; unsigned int i; if (ep->chip->shutdown) return -EBADFD; /* already running? */ if (++ep->use_count != 1) return 0; /* just to be sure */ deactivate_urbs(ep, false); if (can_sleep) wait_clear_urbs(ep); ep->active_mask = 0; ep->unlink_mask = 0; ep->phase = 0; snd_usb_endpoint_start_quirk(ep); /* * If this endpoint has a data endpoint as implicit feedback source, * don't start the urbs here. Instead, mark them all as available, * wait for the record urbs to return and queue the playback urbs * from that context. */ set_bit(EP_FLAG_RUNNING, &ep->flags); if (snd_usb_endpoint_implicit_feedback_sink(ep)) { for (i = 0; i < ep->nurbs; i++) { struct snd_urb_ctx *ctx = ep->urb + i; list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); } return 0; } for (i = 0; i < ep->nurbs; i++) { struct urb *urb = ep->urb[i].urb; if (snd_BUG_ON(!urb)) goto __error; if (usb_pipeout(ep->pipe)) { prepare_outbound_urb(ep, urb->context); } else { prepare_inbound_urb(ep, urb->context); } err = usb_submit_urb(urb, GFP_ATOMIC); if (err < 0) { snd_printk(KERN_ERR "cannot submit urb %d, error %d: %s\n", i, err, usb_error_string(err)); goto __error; } set_bit(i, &ep->active_mask); } return 0; __error: clear_bit(EP_FLAG_RUNNING, &ep->flags); ep->use_count--; deactivate_urbs(ep, false); return -EPIPE; } /** * snd_usb_endpoint_stop: stop an snd_usb_endpoint * * @ep: the endpoint to stop (may be NULL) * * A call to this function will decrement the use count of the endpoint. * In case the last user has requested the endpoint stop, the URBs will * actually be deactivated. * * Must be balanced to calls of snd_usb_endpoint_start(). * * The caller needs to synchronize the pending stop operation via * snd_usb_endpoint_sync_pending_stop(). */ void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep) { if (!ep) return; if (snd_BUG_ON(ep->use_count == 0)) return; if (--ep->use_count == 0) { deactivate_urbs(ep, false); ep->data_subs = NULL; ep->sync_slave = NULL; ep->retire_data_urb = NULL; ep->prepare_data_urb = NULL; set_bit(EP_FLAG_STOPPING, &ep->flags); } } /** * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint * * @ep: the endpoint to deactivate * * If the endpoint is not currently in use, this functions will select the * alternate interface setting 0 for the interface of this endpoint. * * In case of any active users, this functions does nothing. * * Returns an error if usb_set_interface() failed, 0 in all other * cases. */ int snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep) { if (!ep) return -EINVAL; deactivate_urbs(ep, true); wait_clear_urbs(ep); if (ep->use_count != 0) return 0; clear_bit(EP_FLAG_ACTIVATED, &ep->flags); return 0; } /** * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint * * @ep: the list header of the endpoint to free * * This function does not care for the endpoint's use count but will tear * down all the streaming URBs immediately and free all resources. */ void snd_usb_endpoint_free(struct list_head *head) { struct snd_usb_endpoint *ep; ep = list_entry(head, struct snd_usb_endpoint, list); release_urbs(ep, 1); kfree(ep); } /** * snd_usb_handle_sync_urb: parse an USB sync packet * * @ep: the endpoint to handle the packet * @sender: the sending endpoint * @urb: the received packet * * This function is called from the context of an endpoint that received * the packet and is used to let another endpoint object handle the payload. */ void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep, struct snd_usb_endpoint *sender, const struct urb *urb) { int shift; unsigned int f; unsigned long flags; snd_BUG_ON(ep == sender); /* * In case the endpoint is operating in implicit feedback mode, prepare * a new outbound URB that has the same layout as the received packet * and add it to the list of pending urbs. queue_pending_output_urbs() * will take care of them later. */ if (snd_usb_endpoint_implicit_feedback_sink(ep) && ep->use_count != 0) { /* implicit feedback case */ int i, bytes = 0; struct snd_urb_ctx *in_ctx; struct snd_usb_packet_info *out_packet; in_ctx = urb->context; /* Count overall packet size */ for (i = 0; i < in_ctx->packets; i++) if (urb->iso_frame_desc[i].status == 0) bytes += urb->iso_frame_desc[i].actual_length; /* * skip empty packets. At least M-Audio's Fast Track Ultra stops * streaming once it received a 0-byte OUT URB */ if (bytes == 0) return; spin_lock_irqsave(&ep->lock, flags); out_packet = ep->next_packet + ep->next_packet_write_pos; /* * Iterate through the inbound packet and prepare the lengths * for the output packet. The OUT packet we are about to send * will have the same amount of payload bytes per stride as the * IN packet we just received. Since the actual size is scaled * by the stride, use the sender stride to calculate the length * in case the number of channels differ between the implicitly * fed-back endpoint and the synchronizing endpoint. */ out_packet->packets = in_ctx->packets; for (i = 0; i < in_ctx->packets; i++) { if (urb->iso_frame_desc[i].status == 0) out_packet->packet_size[i] = urb->iso_frame_desc[i].actual_length / sender->stride; else out_packet->packet_size[i] = 0; } ep->next_packet_write_pos++; ep->next_packet_write_pos %= MAX_URBS; spin_unlock_irqrestore(&ep->lock, flags); queue_pending_output_urbs(ep); return; } /* * process after playback sync complete * * Full speed devices report feedback values in 10.14 format as samples * per frame, high speed devices in 16.16 format as samples per * microframe. * * Because the Audio Class 1 spec was written before USB 2.0, many high * speed devices use a wrong interpretation, some others use an * entirely different format. * * Therefore, we cannot predict what format any particular device uses * and must detect it automatically. */ if (urb->iso_frame_desc[0].status != 0 || urb->iso_frame_desc[0].actual_length < 3) return; f = le32_to_cpup(urb->transfer_buffer); if (urb->iso_frame_desc[0].actual_length == 3) f &= 0x00ffffff; else f &= 0x0fffffff; if (f == 0) return; if (unlikely(ep->freqshift == INT_MIN)) { /* * The first time we see a feedback value, determine its format * by shifting it left or right until it matches the nominal * frequency value. This assumes that the feedback does not * differ from the nominal value more than +50% or -25%. */ shift = 0; while (f < ep->freqn - ep->freqn / 4) { f <<= 1; shift++; } while (f > ep->freqn + ep->freqn / 2) { f >>= 1; shift--; } ep->freqshift = shift; } else if (ep->freqshift >= 0) f <<= ep->freqshift; else f >>= -ep->freqshift; if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) { /* * If the frequency looks valid, set it. * This value is referred to in prepare_playback_urb(). */ spin_lock_irqsave(&ep->lock, flags); ep->freqm = f; spin_unlock_irqrestore(&ep->lock, flags); } else { /* * Out of range; maybe the shift value is wrong. * Reset it so that we autodetect again the next time. */ ep->freqshift = INT_MIN; } }