linux/sound/usb/usx2y/usb_stream.c
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   1/*
   2 * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms of the GNU General Public License as published by the
   6 * Free Software Foundation; either version 2 of the License, or (at your
   7 * option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful, but
  10 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12 * for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software Foundation,
  16 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19#include <linux/usb.h>
  20#include <linux/gfp.h>
  21
  22#include "usb_stream.h"
  23
  24
  25/*                             setup                                  */
  26
  27static unsigned usb_stream_next_packet_size(struct usb_stream_kernel *sk)
  28{
  29        struct usb_stream *s = sk->s;
  30        sk->out_phase_peeked = (sk->out_phase & 0xffff) + sk->freqn;
  31        return (sk->out_phase_peeked >> 16) * s->cfg.frame_size;
  32}
  33
  34static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb)
  35{
  36        struct usb_stream *s = sk->s;
  37        int pack, lb = 0;
  38
  39        for (pack = 0; pack < sk->n_o_ps; pack++) {
  40                int l = usb_stream_next_packet_size(sk);
  41                if (s->idle_outsize + lb + l > s->period_size)
  42                        goto check;
  43
  44                sk->out_phase = sk->out_phase_peeked;
  45                urb->iso_frame_desc[pack].offset = lb;
  46                urb->iso_frame_desc[pack].length = l;
  47                lb += l;
  48        }
  49        snd_printdd(KERN_DEBUG "%i\n", lb);
  50
  51check:
  52        urb->number_of_packets = pack;
  53        urb->transfer_buffer_length = lb;
  54        s->idle_outsize += lb - s->period_size;
  55        snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
  56                    lb, s->period_size);
  57}
  58
  59static int init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
  60                           struct urb **urbs, char *transfer,
  61                           struct usb_device *dev, int pipe)
  62{
  63        int u, p;
  64        int maxpacket = use_packsize ?
  65                use_packsize : usb_maxpacket(dev, pipe, usb_pipeout(pipe));
  66        int transfer_length = maxpacket * sk->n_o_ps;
  67
  68        for (u = 0; u < USB_STREAM_NURBS;
  69             ++u, transfer += transfer_length) {
  70                struct urb *urb = urbs[u];
  71                struct usb_iso_packet_descriptor *desc;
  72                urb->transfer_buffer = transfer;
  73                urb->dev = dev;
  74                urb->pipe = pipe;
  75                urb->number_of_packets = sk->n_o_ps;
  76                urb->context = sk;
  77                urb->interval = 1;
  78                if (usb_pipeout(pipe))
  79                        continue;
  80                if (usb_urb_ep_type_check(urb))
  81                        return -EINVAL;
  82
  83                urb->transfer_buffer_length = transfer_length;
  84                desc = urb->iso_frame_desc;
  85                desc->offset = 0;
  86                desc->length = maxpacket;
  87                for (p = 1; p < sk->n_o_ps; ++p) {
  88                        desc[p].offset = desc[p - 1].offset + maxpacket;
  89                        desc[p].length = maxpacket;
  90                }
  91        }
  92
  93        return 0;
  94}
  95
  96static int init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
  97                      struct usb_device *dev, int in_pipe, int out_pipe)
  98{
  99        struct usb_stream       *s = sk->s;
 100        char                    *indata = (char *)s + sizeof(*s) +
 101                                        sizeof(struct usb_stream_packet) *
 102                                        s->inpackets;
 103        int                     u;
 104
 105        for (u = 0; u < USB_STREAM_NURBS; ++u) {
 106                sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
 107                sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
 108        }
 109
 110        if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
 111            init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
 112                           out_pipe))
 113                return -EINVAL;
 114
 115        return 0;
 116}
 117
 118
 119/*
 120 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
 121 * this will overflow at approx 524 kHz
 122 */
 123static inline unsigned get_usb_full_speed_rate(unsigned rate)
 124{
 125        return ((rate << 13) + 62) / 125;
 126}
 127
 128/*
 129 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
 130 * this will overflow at approx 4 MHz
 131 */
 132static inline unsigned get_usb_high_speed_rate(unsigned rate)
 133{
 134        return ((rate << 10) + 62) / 125;
 135}
 136
 137void usb_stream_free(struct usb_stream_kernel *sk)
 138{
 139        struct usb_stream *s;
 140        unsigned u;
 141
 142        for (u = 0; u < USB_STREAM_NURBS; ++u) {
 143                usb_free_urb(sk->inurb[u]);
 144                sk->inurb[u] = NULL;
 145                usb_free_urb(sk->outurb[u]);
 146                sk->outurb[u] = NULL;
 147        }
 148
 149        s = sk->s;
 150        if (!s)
 151                return;
 152
 153        free_pages((unsigned long)sk->write_page, get_order(s->write_size));
 154        sk->write_page = NULL;
 155        free_pages((unsigned long)s, get_order(s->read_size));
 156        sk->s = NULL;
 157}
 158
 159struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
 160                                  struct usb_device *dev,
 161                                  unsigned in_endpoint, unsigned out_endpoint,
 162                                  unsigned sample_rate, unsigned use_packsize,
 163                                  unsigned period_frames, unsigned frame_size)
 164{
 165        int packets, max_packsize;
 166        int in_pipe, out_pipe;
 167        int read_size = sizeof(struct usb_stream);
 168        int write_size;
 169        int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
 170        int pg;
 171
 172        in_pipe = usb_rcvisocpipe(dev, in_endpoint);
 173        out_pipe = usb_sndisocpipe(dev, out_endpoint);
 174
 175        max_packsize = use_packsize ?
 176                use_packsize : usb_maxpacket(dev, in_pipe, 0);
 177
 178        /*
 179                t_period = period_frames / sample_rate
 180                iso_packs = t_period / t_iso_frame
 181                        = (period_frames / sample_rate) * (1 / t_iso_frame)
 182        */
 183
 184        packets = period_frames * usb_frames / sample_rate + 1;
 185
 186        if (dev->speed == USB_SPEED_HIGH)
 187                packets = (packets + 7) & ~7;
 188
 189        read_size += packets * USB_STREAM_URBDEPTH *
 190                (max_packsize + sizeof(struct usb_stream_packet));
 191
 192        max_packsize = usb_maxpacket(dev, out_pipe, 1);
 193        write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
 194
 195        if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
 196                snd_printk(KERN_WARNING "a size exceeds 128*PAGE_SIZE\n");
 197                goto out;
 198        }
 199
 200        pg = get_order(read_size);
 201        sk->s = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO|
 202                                          __GFP_NOWARN, pg);
 203        if (!sk->s) {
 204                snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
 205                goto out;
 206        }
 207        sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
 208
 209        sk->s->read_size = read_size;
 210
 211        sk->s->cfg.sample_rate = sample_rate;
 212        sk->s->cfg.frame_size = frame_size;
 213        sk->n_o_ps = packets;
 214        sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
 215        sk->s->cfg.period_frames = period_frames;
 216        sk->s->period_size = frame_size * period_frames;
 217
 218        sk->s->write_size = write_size;
 219        pg = get_order(write_size);
 220
 221        sk->write_page =
 222                (void *)__get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO|
 223                                         __GFP_NOWARN, pg);
 224        if (!sk->write_page) {
 225                snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
 226                usb_stream_free(sk);
 227                return NULL;
 228        }
 229
 230        /* calculate the frequency in 16.16 format */
 231        if (dev->speed == USB_SPEED_FULL)
 232                sk->freqn = get_usb_full_speed_rate(sample_rate);
 233        else
 234                sk->freqn = get_usb_high_speed_rate(sample_rate);
 235
 236        if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
 237                usb_stream_free(sk);
 238                return NULL;
 239        }
 240
 241        sk->s->state = usb_stream_stopped;
 242out:
 243        return sk->s;
 244}
 245
 246
 247/*                             start                                  */
 248
 249static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
 250{
 251        bool r;
 252        if (unlikely(urb->status)) {
 253                if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
 254                        snd_printk(KERN_WARNING "status=%i\n", urb->status);
 255                sk->iso_frame_balance = 0x7FFFFFFF;
 256                return false;
 257        }
 258        r = sk->iso_frame_balance == 0;
 259        if (!r)
 260                sk->i_urb = urb;
 261        return r;
 262}
 263
 264static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
 265{
 266        sk->iso_frame_balance += urb->number_of_packets;
 267        return balance_check(sk, urb);
 268}
 269
 270static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
 271{
 272        sk->iso_frame_balance -= urb->number_of_packets;
 273        return balance_check(sk, urb);
 274}
 275
 276static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
 277{
 278        int u;
 279
 280        for (u = 0; u < USB_STREAM_NURBS; u++) {
 281                struct urb *urb = urbs[u];
 282                urb->complete = complete;
 283        }
 284}
 285
 286static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
 287                struct urb *inurb)
 288{
 289        struct usb_stream *s = sk->s;
 290        struct urb *io;
 291        struct usb_iso_packet_descriptor *id, *od;
 292        int p = 0, lb = 0, l = 0;
 293
 294        io = sk->idle_outurb;
 295        od = io->iso_frame_desc;
 296
 297        for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
 298                struct urb *ii = sk->completed_inurb;
 299                id = ii->iso_frame_desc +
 300                        ii->number_of_packets + s->sync_packet;
 301                l = id->actual_length;
 302
 303                od[p].length = l;
 304                od[p].offset = lb;
 305                lb += l;
 306        }
 307
 308        for (;
 309             s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
 310             ++p, ++s->sync_packet) {
 311                l = inurb->iso_frame_desc[s->sync_packet].actual_length;
 312
 313                if (s->idle_outsize + lb + l > s->period_size)
 314                        goto check_ok;
 315
 316                od[p].length = l;
 317                od[p].offset = lb;
 318                lb += l;
 319        }
 320
 321check_ok:
 322        s->sync_packet -= inurb->number_of_packets;
 323        if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
 324                snd_printk(KERN_WARNING "invalid sync_packet = %i;"
 325                           " p=%i nop=%i %i %x %x %x > %x\n",
 326                           s->sync_packet, p, inurb->number_of_packets,
 327                           s->idle_outsize + lb + l,
 328                           s->idle_outsize, lb,  l,
 329                           s->period_size);
 330                return -1;
 331        }
 332        if (unlikely(lb % s->cfg.frame_size)) {
 333                snd_printk(KERN_WARNING"invalid outsize = %i\n",
 334                           lb);
 335                return -1;
 336        }
 337        s->idle_outsize += lb - s->period_size;
 338        io->number_of_packets = p;
 339        io->transfer_buffer_length = lb;
 340        if (s->idle_outsize <= 0)
 341                return 0;
 342
 343        snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
 344        return -1;
 345}
 346
 347static void prepare_inurb(int number_of_packets, struct urb *iu)
 348{
 349        struct usb_iso_packet_descriptor *id;
 350        int p;
 351
 352        iu->number_of_packets = number_of_packets;
 353        id = iu->iso_frame_desc;
 354        id->offset = 0;
 355        for (p = 0; p < iu->number_of_packets - 1; ++p)
 356                id[p + 1].offset = id[p].offset + id[p].length;
 357
 358        iu->transfer_buffer_length =
 359                id[0].length * iu->number_of_packets;
 360}
 361
 362static int submit_urbs(struct usb_stream_kernel *sk,
 363                       struct urb *inurb, struct urb *outurb)
 364{
 365        int err;
 366        prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
 367        err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
 368        if (err < 0)
 369                goto report_failure;
 370
 371        sk->idle_inurb = sk->completed_inurb;
 372        sk->completed_inurb = inurb;
 373        err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
 374        if (err < 0)
 375                goto report_failure;
 376
 377        sk->idle_outurb = sk->completed_outurb;
 378        sk->completed_outurb = outurb;
 379        return 0;
 380
 381report_failure:
 382        snd_printk(KERN_ERR "%i\n", err);
 383        return err;
 384}
 385
 386#ifdef DEBUG_LOOP_BACK
 387/*
 388  This loop_back() shows how to read/write the period data.
 389 */
 390static void loop_back(struct usb_stream *s)
 391{
 392        char *i, *o;
 393        int il, ol, l, p;
 394        struct urb *iu;
 395        struct usb_iso_packet_descriptor *id;
 396
 397        o = s->playback1st_to;
 398        ol = s->playback1st_size;
 399        l = 0;
 400
 401        if (s->insplit_pack >= 0) {
 402                iu = sk->idle_inurb;
 403                id = iu->iso_frame_desc;
 404                p = s->insplit_pack;
 405        } else
 406                goto second;
 407loop:
 408        for (; p < iu->number_of_packets && l < s->period_size; ++p) {
 409                i = iu->transfer_buffer + id[p].offset;
 410                il = id[p].actual_length;
 411                if (l + il > s->period_size)
 412                        il = s->period_size - l;
 413                if (il <= ol) {
 414                        memcpy(o, i, il);
 415                        o += il;
 416                        ol -= il;
 417                } else {
 418                        memcpy(o, i, ol);
 419                        singen_6pack(o, ol);
 420                        o = s->playback_to;
 421                        memcpy(o, i + ol, il - ol);
 422                        o += il - ol;
 423                        ol = s->period_size - s->playback1st_size;
 424                }
 425                l += il;
 426        }
 427        if (iu == sk->completed_inurb) {
 428                if (l != s->period_size)
 429                        printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
 430                               l/(int)s->cfg.frame_size);
 431
 432                return;
 433        }
 434second:
 435        iu = sk->completed_inurb;
 436        id = iu->iso_frame_desc;
 437        p = 0;
 438        goto loop;
 439
 440}
 441#else
 442static void loop_back(struct usb_stream *s)
 443{
 444}
 445#endif
 446
 447static void stream_idle(struct usb_stream_kernel *sk,
 448                        struct urb *inurb, struct urb *outurb)
 449{
 450        struct usb_stream *s = sk->s;
 451        int l, p;
 452        int insize = s->idle_insize;
 453        int urb_size = 0;
 454
 455        s->inpacket_split = s->next_inpacket_split;
 456        s->inpacket_split_at = s->next_inpacket_split_at;
 457        s->next_inpacket_split = -1;
 458        s->next_inpacket_split_at = 0;
 459
 460        for (p = 0; p < inurb->number_of_packets; ++p) {
 461                struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
 462                l = id[p].actual_length;
 463                if (unlikely(l == 0 || id[p].status)) {
 464                        snd_printk(KERN_WARNING "underrun, status=%u\n",
 465                                   id[p].status);
 466                        goto err_out;
 467                }
 468                s->inpacket_head++;
 469                s->inpacket_head %= s->inpackets;
 470                if (s->inpacket_split == -1)
 471                        s->inpacket_split = s->inpacket_head;
 472
 473                s->inpacket[s->inpacket_head].offset =
 474                        id[p].offset + (inurb->transfer_buffer - (void *)s);
 475                s->inpacket[s->inpacket_head].length = l;
 476                if (insize + l > s->period_size &&
 477                    s->next_inpacket_split == -1) {
 478                        s->next_inpacket_split = s->inpacket_head;
 479                        s->next_inpacket_split_at = s->period_size - insize;
 480                }
 481                insize += l;
 482                urb_size += l;
 483        }
 484        s->idle_insize += urb_size - s->period_size;
 485        if (s->idle_insize < 0) {
 486                snd_printk(KERN_WARNING "%i\n",
 487                           (s->idle_insize)/(int)s->cfg.frame_size);
 488                goto err_out;
 489        }
 490        s->insize_done += urb_size;
 491
 492        l = s->idle_outsize;
 493        s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
 494                                  sk->write_page) - l;
 495
 496        if (usb_stream_prepare_playback(sk, inurb) < 0)
 497                goto err_out;
 498
 499        s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
 500        s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
 501                sk->write_page;
 502
 503        if (submit_urbs(sk, inurb, outurb) < 0)
 504                goto err_out;
 505
 506        loop_back(s);
 507        s->periods_done++;
 508        wake_up_all(&sk->sleep);
 509        return;
 510err_out:
 511        s->state = usb_stream_xrun;
 512        wake_up_all(&sk->sleep);
 513}
 514
 515static void i_capture_idle(struct urb *urb)
 516{
 517        struct usb_stream_kernel *sk = urb->context;
 518        if (balance_capture(sk, urb))
 519                stream_idle(sk, urb, sk->i_urb);
 520}
 521
 522static void i_playback_idle(struct urb *urb)
 523{
 524        struct usb_stream_kernel *sk = urb->context;
 525        if (balance_playback(sk, urb))
 526                stream_idle(sk, sk->i_urb, urb);
 527}
 528
 529static void stream_start(struct usb_stream_kernel *sk,
 530                         struct urb *inurb, struct urb *outurb)
 531{
 532        struct usb_stream *s = sk->s;
 533        if (s->state >= usb_stream_sync1) {
 534                int l, p, max_diff, max_diff_0;
 535                int urb_size = 0;
 536                unsigned frames_per_packet, min_frames = 0;
 537                frames_per_packet = (s->period_size - s->idle_insize);
 538                frames_per_packet <<= 8;
 539                frames_per_packet /=
 540                        s->cfg.frame_size * inurb->number_of_packets;
 541                frames_per_packet++;
 542
 543                max_diff_0 = s->cfg.frame_size;
 544                if (s->cfg.period_frames >= 256)
 545                        max_diff_0 <<= 1;
 546                if (s->cfg.period_frames >= 1024)
 547                        max_diff_0 <<= 1;
 548                max_diff = max_diff_0;
 549                for (p = 0; p < inurb->number_of_packets; ++p) {
 550                        int diff;
 551                        l = inurb->iso_frame_desc[p].actual_length;
 552                        urb_size += l;
 553
 554                        min_frames += frames_per_packet;
 555                        diff = urb_size -
 556                                (min_frames >> 8) * s->cfg.frame_size;
 557                        if (diff < max_diff) {
 558                                snd_printdd(KERN_DEBUG "%i %i %i %i\n",
 559                                            s->insize_done,
 560                                            urb_size / (int)s->cfg.frame_size,
 561                                            inurb->number_of_packets, diff);
 562                                max_diff = diff;
 563                        }
 564                }
 565                s->idle_insize -= max_diff - max_diff_0;
 566                s->idle_insize += urb_size - s->period_size;
 567                if (s->idle_insize < 0) {
 568                        snd_printk(KERN_WARNING "%i %i %i\n",
 569                                   s->idle_insize, urb_size, s->period_size);
 570                        return;
 571                } else if (s->idle_insize == 0) {
 572                        s->next_inpacket_split =
 573                                (s->inpacket_head + 1) % s->inpackets;
 574                        s->next_inpacket_split_at = 0;
 575                } else {
 576                        unsigned split = s->inpacket_head;
 577                        l = s->idle_insize;
 578                        while (l > s->inpacket[split].length) {
 579                                l -= s->inpacket[split].length;
 580                                if (split == 0)
 581                                        split = s->inpackets - 1;
 582                                else
 583                                        split--;
 584                        }
 585                        s->next_inpacket_split = split;
 586                        s->next_inpacket_split_at =
 587                                s->inpacket[split].length - l;
 588                }
 589
 590                s->insize_done += urb_size;
 591
 592                if (usb_stream_prepare_playback(sk, inurb) < 0)
 593                        return;
 594
 595        } else
 596                playback_prep_freqn(sk, sk->idle_outurb);
 597
 598        if (submit_urbs(sk, inurb, outurb) < 0)
 599                return;
 600
 601        if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
 602                /* just guesswork                            ^^^^^^ */
 603                s->state = usb_stream_ready;
 604                subs_set_complete(sk->inurb, i_capture_idle);
 605                subs_set_complete(sk->outurb, i_playback_idle);
 606        }
 607}
 608
 609static void i_capture_start(struct urb *urb)
 610{
 611        struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
 612        struct usb_stream_kernel *sk = urb->context;
 613        struct usb_stream *s = sk->s;
 614        int p;
 615        int empty = 0;
 616
 617        if (urb->status) {
 618                snd_printk(KERN_WARNING "status=%i\n", urb->status);
 619                return;
 620        }
 621
 622        for (p = 0; p < urb->number_of_packets; ++p) {
 623                int l = id[p].actual_length;
 624                if (l < s->cfg.frame_size) {
 625                        ++empty;
 626                        if (s->state >= usb_stream_sync0) {
 627                                snd_printk(KERN_WARNING "%i\n", l);
 628                                return;
 629                        }
 630                }
 631                s->inpacket_head++;
 632                s->inpacket_head %= s->inpackets;
 633                s->inpacket[s->inpacket_head].offset =
 634                        id[p].offset + (urb->transfer_buffer - (void *)s);
 635                s->inpacket[s->inpacket_head].length = l;
 636        }
 637#ifdef SHOW_EMPTY
 638        if (empty) {
 639                printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
 640                       urb->iso_frame_desc[0].actual_length);
 641                for (pack = 1; pack < urb->number_of_packets; ++pack) {
 642                        int l = urb->iso_frame_desc[pack].actual_length;
 643                        printk(KERN_CONT " %i", l);
 644                }
 645                printk(KERN_CONT "\n");
 646        }
 647#endif
 648        if (!empty && s->state < usb_stream_sync1)
 649                ++s->state;
 650
 651        if (balance_capture(sk, urb))
 652                stream_start(sk, urb, sk->i_urb);
 653}
 654
 655static void i_playback_start(struct urb *urb)
 656{
 657        struct usb_stream_kernel *sk = urb->context;
 658        if (balance_playback(sk, urb))
 659                stream_start(sk, sk->i_urb, urb);
 660}
 661
 662int usb_stream_start(struct usb_stream_kernel *sk)
 663{
 664        struct usb_stream *s = sk->s;
 665        int frame = 0, iters = 0;
 666        int u, err;
 667        int try = 0;
 668
 669        if (s->state != usb_stream_stopped)
 670                return -EAGAIN;
 671
 672        subs_set_complete(sk->inurb, i_capture_start);
 673        subs_set_complete(sk->outurb, i_playback_start);
 674        memset(sk->write_page, 0, s->write_size);
 675dotry:
 676        s->insize_done = 0;
 677        s->idle_insize = 0;
 678        s->idle_outsize = 0;
 679        s->sync_packet = -1;
 680        s->inpacket_head = -1;
 681        sk->iso_frame_balance = 0;
 682        ++try;
 683        for (u = 0; u < 2; u++) {
 684                struct urb *inurb = sk->inurb[u];
 685                struct urb *outurb = sk->outurb[u];
 686                playback_prep_freqn(sk, outurb);
 687                inurb->number_of_packets = outurb->number_of_packets;
 688                inurb->transfer_buffer_length =
 689                        inurb->number_of_packets *
 690                        inurb->iso_frame_desc[0].length;
 691
 692                if (u == 0) {
 693                        int now;
 694                        struct usb_device *dev = inurb->dev;
 695                        frame = usb_get_current_frame_number(dev);
 696                        do {
 697                                now = usb_get_current_frame_number(dev);
 698                                ++iters;
 699                        } while (now > -1 && now == frame);
 700                }
 701                err = usb_submit_urb(inurb, GFP_ATOMIC);
 702                if (err < 0) {
 703                        snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
 704                                   " returned %i\n", u, err);
 705                        return err;
 706                }
 707                err = usb_submit_urb(outurb, GFP_ATOMIC);
 708                if (err < 0) {
 709                        snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
 710                                   " returned %i\n", u, err);
 711                        return err;
 712                }
 713
 714                if (inurb->start_frame != outurb->start_frame) {
 715                        snd_printd(KERN_DEBUG
 716                                   "u[%i] start_frames differ in:%u out:%u\n",
 717                                   u, inurb->start_frame, outurb->start_frame);
 718                        goto check_retry;
 719                }
 720        }
 721        snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
 722        try = 0;
 723check_retry:
 724        if (try) {
 725                usb_stream_stop(sk);
 726                if (try < 5) {
 727                        msleep(1500);
 728                        snd_printd(KERN_DEBUG "goto dotry;\n");
 729                        goto dotry;
 730                }
 731                snd_printk(KERN_WARNING"couldn't start"
 732                           " all urbs on the same start_frame.\n");
 733                return -EFAULT;
 734        }
 735
 736        sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
 737        sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
 738        sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
 739        sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
 740
 741/* wait, check */
 742        {
 743                int wait_ms = 3000;
 744                while (s->state != usb_stream_ready && wait_ms > 0) {
 745                        snd_printdd(KERN_DEBUG "%i\n", s->state);
 746                        msleep(200);
 747                        wait_ms -= 200;
 748                }
 749        }
 750
 751        return s->state == usb_stream_ready ? 0 : -EFAULT;
 752}
 753
 754
 755/*                             stop                                   */
 756
 757void usb_stream_stop(struct usb_stream_kernel *sk)
 758{
 759        int u;
 760        if (!sk->s)
 761                return;
 762        for (u = 0; u < USB_STREAM_NURBS; ++u) {
 763                usb_kill_urb(sk->inurb[u]);
 764                usb_kill_urb(sk->outurb[u]);
 765        }
 766        sk->s->state = usb_stream_stopped;
 767        msleep(400);
 768}
 769