code.delx.au - pulseaudio/blob - src/modules/module-udev-detect.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2009 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27 #include <limits.h>
  28 #include <dirent.h>
  29 #include <sys/inotify.h>
  30 #include <libudev.h>
  31
  32 #include <pulse/timeval.h>
  33
  34 #include <pulsecore/modargs.h>
  35 #include <pulsecore/core-error.h>
  36 #include <pulsecore/core-util.h>
  37 #include <pulsecore/namereg.h>
  38 #include <pulsecore/ratelimit.h>
  39
  40 #include "module-udev-detect-symdef.h"
  41
  42 PA_MODULE_AUTHOR("Lennart Poettering");
  43 PA_MODULE_DESCRIPTION("Detect available audio hardware and load matching drivers");
  44 PA_MODULE_VERSION(PACKAGE_VERSION);
  45 PA_MODULE_LOAD_ONCE(TRUE);
  46 PA_MODULE_USAGE(
  47         "tsched=<enable system timer based scheduling mode?> "
  48         "ignore_dB=<ignore dB information from the device?>");
  49
  50 struct device {
  51     char *path;
  52     pa_bool_t need_verify;
  53     char *card_name;
  54     char *args;
  55     uint32_t module;
  56     pa_ratelimit ratelimit;
  57 };
  58
  59 struct userdata {
  60     pa_core *core;
  61     pa_hashmap *devices;
  62
  63     pa_bool_t use_tsched:1;
  64     pa_bool_t ignore_dB:1;
  65
  66     struct udev* udev;
  67     struct udev_monitor *monitor;
  68     pa_io_event *udev_io;
  69
  70     int inotify_fd;
  71     pa_io_event *inotify_io;
  72 };
  73
  74 static const char* const valid_modargs[] = {
  75     "tsched",
  76     "ignore_dB",
  77     NULL
  78 };
  79
  80 static int setup_inotify(struct userdata *u);
  81
  82 static void device_free(struct device *d) {
  83     pa_assert(d);
  84
  85     pa_xfree(d->path);
  86     pa_xfree(d->card_name);
  87     pa_xfree(d->args);
  88     pa_xfree(d);
  89 }
  90
  91 static const char *path_get_card_id(const char *path) {
  92     const char *e;
  93
  94     if (!path)
  95         return NULL;
  96
  97     if (!(e = strrchr(path, '/')))
  98         return NULL;
  99
 100     if (!pa_startswith(e, "/card"))
 101         return NULL;
 102
 103     return e + 5;
 104 }
 105
 106 static char *card_get_sysattr(const char *card_idx, const char *name) {
 107     struct udev *udev;
 108     struct udev_device *card = NULL;
 109     char *t, *r = NULL;
 110     const char *v;
 111
 112     pa_assert(card_idx);
 113     pa_assert(name);
 114
 115     if (!(udev = udev_new())) {
 116         pa_log_error("Failed to allocate udev context.");
 117         goto finish;
 118     }
 119
 120     t = pa_sprintf_malloc("%s/class/sound/card%s", udev_get_sys_path(udev), card_idx);
 121     card = udev_device_new_from_syspath(udev, t);
 122     pa_xfree(t);
 123
 124     if (!card) {
 125         pa_log_error("Failed to get card object.");
 126         goto finish;
 127     }
 128
 129     if ((v = udev_device_get_sysattr_value(card, name)) && *v)
 130         r = pa_xstrdup(v);
 131
 132 finish:
 133
 134     if (card)
 135         udev_device_unref(card);
 136
 137     if (udev)
 138         udev_unref(udev);
 139
 140     return r;
 141 }
 142
 143 static pa_bool_t pcm_is_modem(const char *card_idx, const char *pcm) {
 144     char *sysfs_path, *pcm_class;
 145     pa_bool_t is_modem;
 146
 147     pa_assert(card_idx);
 148     pa_assert(pcm);
 149
 150     /* Check /sys/class/sound/card.../pcmC...../pcm_class. An HDA
 151      * modem can be used simultaneously with generic
 152      * playback/record. */
 153
 154     sysfs_path = pa_sprintf_malloc("pcmC%sD%s/pcm_class", card_idx, pcm);
 155     pcm_class = card_get_sysattr(card_idx, sysfs_path);
 156     is_modem = pcm_class && pa_streq(pcm_class, "modem");
 157     pa_xfree(pcm_class);
 158     pa_xfree(sysfs_path);
 159
 160     return is_modem;
 161 }
 162
 163 static pa_bool_t is_card_busy(const char *id) {
 164     char *card_path = NULL, *pcm_path = NULL, *sub_status = NULL;
 165     DIR *card_dir = NULL, *pcm_dir = NULL;
 166     FILE *status_file = NULL;
 167     size_t len;
 168     struct dirent *space = NULL, *de;
 169     pa_bool_t busy = FALSE;
 170     int r;
 171
 172     pa_assert(id);
 173
 174     /* This simply uses /proc/asound/card.../pcm.../sub.../status to
 175      * check whether there is still a process using this audio device. */
 176
 177     card_path = pa_sprintf_malloc("/proc/asound/card%s", id);
 178
 179     if (!(card_dir = opendir(card_path))) {
 180         pa_log_warn("Failed to open %s: %s", card_path, pa_cstrerror(errno));
 181         goto fail;
 182     }
 183
 184     len = offsetof(struct dirent, d_name) + fpathconf(dirfd(card_dir), _PC_NAME_MAX) + 1;
 185     space = pa_xmalloc(len);
 186
 187     for (;;) {
 188         de = NULL;
 189
 190         if ((r = readdir_r(card_dir, space, &de)) != 0) {
 191             pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
 192             goto fail;
 193         }
 194
 195         if (!de)
 196             break;
 197
 198         if (!pa_startswith(de->d_name, "pcm"))
 199             continue;
 200
 201         if (pcm_is_modem(id, de->d_name + 3))
 202             continue;
 203
 204         pa_xfree(pcm_path);
 205         pcm_path = pa_sprintf_malloc("%s/%s", card_path, de->d_name);
 206
 207         if (pcm_dir)
 208             closedir(pcm_dir);
 209
 210         if (!(pcm_dir = opendir(pcm_path))) {
 211             pa_log_warn("Failed to open %s: %s", pcm_path, pa_cstrerror(errno));
 212             continue;
 213         }
 214
 215         for (;;) {
 216             char line[32];
 217
 218             if ((r = readdir_r(pcm_dir, space, &de)) != 0) {
 219                 pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
 220                 goto fail;
 221             }
 222
 223             if (!de)
 224                 break;
 225
 226             if (!pa_startswith(de->d_name, "sub"))
 227                 continue;
 228
 229             pa_xfree(sub_status);
 230             sub_status = pa_sprintf_malloc("%s/%s/status", pcm_path, de->d_name);
 231
 232             if (status_file)
 233                 fclose(status_file);
 234
 235             if (!(status_file = pa_fopen_cloexec(sub_status, "r"))) {
 236                 pa_log_warn("Failed to open %s: %s", sub_status, pa_cstrerror(errno));
 237                 continue;
 238             }
 239
 240             if (!(fgets(line, sizeof(line)-1, status_file))) {
 241                 pa_log_warn("Failed to read from %s: %s", sub_status, pa_cstrerror(errno));
 242                 continue;
 243             }
 244
 245             if (!pa_streq(line, "closed\n")) {
 246                 busy = TRUE;
 247                 break;
 248             }
 249         }
 250     }
 251
 252 fail:
 253
 254     pa_xfree(card_path);
 255     pa_xfree(pcm_path);
 256     pa_xfree(sub_status);
 257     pa_xfree(space);
 258
 259     if (card_dir)
 260         closedir(card_dir);
 261
 262     if (pcm_dir)
 263         closedir(pcm_dir);
 264
 265     if (status_file)
 266         fclose(status_file);
 267
 268     return busy;
 269 }
 270
 271 static void verify_access(struct userdata *u, struct device *d) {
 272     char *cd;
 273     pa_card *card;
 274     pa_bool_t accessible;
 275
 276     pa_assert(u);
 277     pa_assert(d);
 278
 279     cd = pa_sprintf_malloc("%s/snd/controlC%s", udev_get_dev_path(u->udev), path_get_card_id(d->path));
 280     accessible = access(cd, R_OK|W_OK) >= 0;
 281     pa_log_debug("%s is accessible: %s", cd, pa_yes_no(accessible));
 282
 283     pa_xfree(cd);
 284
 285     if (d->module == PA_INVALID_INDEX) {
 286
 287         /* If we are not loaded, try to load */
 288
 289         if (accessible) {
 290             pa_module *m;
 291             pa_bool_t busy;
 292
 293             /* Check if any of the PCM devices that belong to this
 294              * card are currently busy. If they are, don't try to load
 295              * right now, to make sure the probing phase can
 296              * successfully complete. When the current user of the
 297              * device closes it we will get another notification via
 298              * inotify and can then recheck. */
 299
 300             busy = is_card_busy(path_get_card_id(d->path));
 301             pa_log_debug("%s is busy: %s", d->path, pa_yes_no(busy));
 302
 303             if (!busy) {
 304
 305                 /* So, why do we rate limit here? It's certainly ugly,
 306                  * but there seems to be no other way. Problem is
 307                  * this: if we are unable to configure/probe an audio
 308                  * device after opening it we will close it again and
 309                  * the module initialization will fail. This will then
 310                  * cause an inotify event on the device node which
 311                  * will be forwarded to us. We then try to reopen the
 312                  * audio device again, practically entering a busy
 313                  * loop.
 314                  *
 315                  * A clean fix would be if we would be able to ignore
 316                  * our own inotify close events. However, inotify
 317                  * lacks such functionality. Also, during probing of
 318                  * the device we cannot really distuingish between
 319                  * other processes causing EBUSY or ourselves, which
 320                  * means we have no way to figure out if the probing
 321                  * during opening was canceled by a "try again"
 322                  * failure or a "fatal" failure. */
 323
 324                 if (pa_ratelimit_test(&d->ratelimit)) {
 325                     pa_log_debug("Loading module-alsa-card with arguments '%s'", d->args);
 326                     m = pa_module_load(u->core, "module-alsa-card", d->args);
 327
 328                     if (m) {
 329                         d->module = m->index;
 330                         pa_log_info("Card %s (%s) module loaded.", d->path, d->card_name);
 331                     } else
 332                         pa_log_info("Card %s (%s) failed to load module.", d->path, d->card_name);
 333                 } else
 334                     pa_log_warn("Tried to configure %s (%s) more often than %u times in %llus",
 335                                 d->path,
 336                                 d->card_name,
 337                                 d->ratelimit.burst,
 338                                 (long long unsigned) (d->ratelimit.interval / PA_USEC_PER_SEC));
 339             }
 340         }
 341
 342     } else {
 343
 344         /* If we are already loaded update suspend status with
 345          * accessible boolean */
 346
 347         if ((card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
 348             pa_card_suspend(card, !accessible, PA_SUSPEND_SESSION);
 349     }
 350 }
 351
 352 static void card_changed(struct userdata *u, struct udev_device *dev) {
 353     struct device *d;
 354     const char *path;
 355     const char *t;
 356     char *n;
 357
 358     pa_assert(u);
 359     pa_assert(dev);
 360
 361     /* Maybe /dev/snd is now available? */
 362     setup_inotify(u);
 363
 364     path = udev_device_get_devpath(dev);
 365
 366     if ((d = pa_hashmap_get(u->devices, path))) {
 367         verify_access(u, d);
 368         return;
 369     }
 370
 371     d = pa_xnew0(struct device, 1);
 372     d->path = pa_xstrdup(path);
 373     d->module = PA_INVALID_INDEX;
 374     PA_INIT_RATELIMIT(d->ratelimit, 10*PA_USEC_PER_SEC, 5);
 375
 376     if (!(t = udev_device_get_property_value(dev, "PULSE_NAME")))
 377         if (!(t = udev_device_get_property_value(dev, "ID_ID")))
 378             if (!(t = udev_device_get_property_value(dev, "ID_PATH")))
 379                 t = path_get_card_id(path);
 380
 381     n = pa_namereg_make_valid_name(t);
 382     d->card_name = pa_sprintf_malloc("alsa_card.%s", n);
 383     d->args = pa_sprintf_malloc("device_id=\"%s\" "
 384                                 "name=\"%s\" "
 385                                 "card_name=\"%s\" "
 386                                 "namereg_fail=false "
 387                                 "tsched=%s "
 388                                 "ignore_dB=%s "
 389                                 "card_properties=\"module-udev-detect.discovered=1\"",
 390                                 path_get_card_id(path),
 391                                 n,
 392                                 d->card_name,
 393                                 pa_yes_no(u->use_tsched),
 394                                 pa_yes_no(u->ignore_dB));
 395     pa_xfree(n);
 396
 397     pa_hashmap_put(u->devices, d->path, d);
 398
 399     verify_access(u, d);
 400 }
 401
 402 static void remove_card(struct userdata *u, struct udev_device *dev) {
 403     struct device *d;
 404
 405     pa_assert(u);
 406     pa_assert(dev);
 407
 408     if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
 409         return;
 410
 411     pa_log_info("Card %s removed.", d->path);
 412
 413     if (d->module != PA_INVALID_INDEX)
 414         pa_module_unload_request_by_index(u->core, d->module, TRUE);
 415
 416     device_free(d);
 417 }
 418
 419 static void process_device(struct userdata *u, struct udev_device *dev) {
 420     const char *action, *ff;
 421
 422     pa_assert(u);
 423     pa_assert(dev);
 424
 425     if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
 426         pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
 427         return;
 428     }
 429
 430     if ((ff = udev_device_get_property_value(dev, "SOUND_CLASS")) &&
 431         pa_streq(ff, "modem")) {
 432         pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
 433         return;
 434     }
 435
 436     action = udev_device_get_action(dev);
 437
 438     if (action && pa_streq(action, "remove"))
 439         remove_card(u, dev);
 440     else if ((!action || pa_streq(action, "change")) &&
 441              udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
 442         card_changed(u, dev);
 443
 444     /* For an explanation why we don't look for 'add' events here
 445      * have a look into /lib/udev/rules.d/78-sound-card.rules! */
 446 }
 447
 448 static void process_path(struct userdata *u, const char *path) {
 449     struct udev_device *dev;
 450
 451     if (!path_get_card_id(path))
 452         return;
 453
 454     if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
 455         pa_log("Failed to get udev device object from udev.");
 456         return;
 457     }
 458
 459     process_device(u, dev);
 460     udev_device_unref(dev);
 461 }
 462
 463 static void monitor_cb(
 464         pa_mainloop_api*a,
 465         pa_io_event* e,
 466         int fd,
 467         pa_io_event_flags_t events,
 468         void *userdata) {
 469
 470     struct userdata *u = userdata;
 471     struct udev_device *dev;
 472
 473     pa_assert(a);
 474
 475     if (!(dev = udev_monitor_receive_device(u->monitor))) {
 476         pa_log("Failed to get udev device object from monitor.");
 477         goto fail;
 478     }
 479
 480     if (!path_get_card_id(udev_device_get_devpath(dev))) {
 481         udev_device_unref(dev);
 482         return;
 483     }
 484
 485     process_device(u, dev);
 486     udev_device_unref(dev);
 487     return;
 488
 489 fail:
 490     a->io_free(u->udev_io);
 491     u->udev_io = NULL;
 492 }
 493
 494 static pa_bool_t pcm_node_belongs_to_device(
 495         struct device *d,
 496         const char *node) {
 497
 498     char *cd;
 499     pa_bool_t b;
 500
 501     cd = pa_sprintf_malloc("pcmC%sD", path_get_card_id(d->path));
 502     b = pa_startswith(node, cd);
 503     pa_xfree(cd);
 504
 505     return b;
 506 }
 507
 508 static pa_bool_t control_node_belongs_to_device(
 509         struct device *d,
 510         const char *node) {
 511
 512     char *cd;
 513     pa_bool_t b;
 514
 515     cd = pa_sprintf_malloc("controlC%s", path_get_card_id(d->path));
 516     b = pa_streq(node, cd);
 517     pa_xfree(cd);
 518
 519     return b;
 520 }
 521
 522 static void inotify_cb(
 523         pa_mainloop_api*a,
 524         pa_io_event* e,
 525         int fd,
 526         pa_io_event_flags_t events,
 527         void *userdata) {
 528
 529     struct {
 530         struct inotify_event e;
 531         char name[NAME_MAX];
 532     } buf;
 533     struct userdata *u = userdata;
 534     static int type = 0;
 535     pa_bool_t deleted = FALSE;
 536     struct device *d;
 537     void *state;
 538
 539     for (;;) {
 540         ssize_t r;
 541         struct inotify_event *event;
 542
 543         pa_zero(buf);
 544         if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
 545
 546             if (r < 0 && errno == EAGAIN)
 547                 break;
 548
 549             pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
 550             goto fail;
 551         }
 552
 553         event = &buf.e;
 554         while (r > 0) {
 555             size_t len;
 556
 557             if ((size_t) r < sizeof(struct inotify_event)) {
 558                 pa_log("read() too short.");
 559                 goto fail;
 560             }
 561
 562             len = sizeof(struct inotify_event) + event->len;
 563
 564             if ((size_t) r < len) {
 565                 pa_log("Payload missing.");
 566                 goto fail;
 567             }
 568
 569             /* From udev we get the guarantee that the control
 570              * device's ACL is changed last. To avoid races when ACLs
 571              * are changed we hence watch only the control device */
 572             if (((event->mask & IN_ATTRIB) && pa_startswith(event->name, "controlC")))
 573                 PA_HASHMAP_FOREACH(d, u->devices, state)
 574                     if (control_node_belongs_to_device(d, event->name))
 575                         d->need_verify = TRUE;
 576
 577             /* ALSA doesn't really give us any guarantee on the closing
 578              * order, so let's simply hope */
 579             if (((event->mask & IN_CLOSE_WRITE) && pa_startswith(event->name, "pcmC")))
 580                 PA_HASHMAP_FOREACH(d, u->devices, state)
 581                     if (pcm_node_belongs_to_device(d, event->name))
 582                         d->need_verify = TRUE;
 583
 584             /* /dev/snd/ might have been removed */
 585             if ((event->mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
 586                 deleted = TRUE;
 587
 588             event = (struct inotify_event*) ((uint8_t*) event + len);
 589             r -= len;
 590         }
 591     }
 592
 593     PA_HASHMAP_FOREACH(d, u->devices, state)
 594         if (d->need_verify) {
 595             d->need_verify = FALSE;
 596             verify_access(u, d);
 597         }
 598
 599     if (!deleted)
 600         return;
 601
 602 fail:
 603     if (u->inotify_io) {
 604         a->io_free(u->inotify_io);
 605         u->inotify_io = NULL;
 606     }
 607
 608     if (u->inotify_fd >= 0) {
 609         pa_close(u->inotify_fd);
 610         u->inotify_fd = -1;
 611     }
 612 }
 613
 614 static int setup_inotify(struct userdata *u) {
 615     char *dev_snd;
 616     int r;
 617
 618     if (u->inotify_fd >= 0)
 619         return 0;
 620
 621     if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
 622         pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
 623         return -1;
 624     }
 625
 626     dev_snd = pa_sprintf_malloc("%s/snd", udev_get_dev_path(u->udev));
 627     r = inotify_add_watch(u->inotify_fd, dev_snd, IN_ATTRIB|IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
 628     pa_xfree(dev_snd);
 629
 630     if (r < 0) {
 631         int saved_errno = errno;
 632
 633         pa_close(u->inotify_fd);
 634         u->inotify_fd = -1;
 635
 636         if (saved_errno == ENOENT) {
 637             pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
 638             return 0;
 639         }
 640
 641         if (saved_errno == ENOSPC) {
 642             pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
 643                    "I wished people would do their homework first and fix inotify before using it for watching whole "
 644                    "directory trees which is something the current inotify is certainly not useful for. "
 645                    "Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
 646             return 0;
 647         }
 648
 649         pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
 650         return -1;
 651     }
 652
 653     pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
 654
 655     return 0;
 656 }
 657
 658 int pa__init(pa_module *m) {
 659     struct userdata *u = NULL;
 660     pa_modargs *ma;
 661     struct udev_enumerate *enumerate = NULL;
 662     struct udev_list_entry *item = NULL, *first = NULL;
 663     int fd;
 664     pa_bool_t use_tsched = TRUE, ignore_dB = FALSE;
 665
 666     pa_assert(m);
 667
 668     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
 669         pa_log("Failed to parse module arguments");
 670         goto fail;
 671     }
 672
 673     m->userdata = u = pa_xnew0(struct userdata, 1);
 674     u->core = m->core;
 675     u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
 676     u->inotify_fd = -1;
 677
 678     if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
 679         pa_log("Failed to parse tsched= argument.");
 680         goto fail;
 681     }
 682     u->use_tsched = use_tsched;
 683
 684     if (pa_modargs_get_value_boolean(ma, "ignore_dB", &ignore_dB) < 0) {
 685         pa_log("Failed to parse ignore_dB= argument.");
 686         goto fail;
 687     }
 688     u->ignore_dB = ignore_dB;
 689
 690     if (!(u->udev = udev_new())) {
 691         pa_log("Failed to initialize udev library.");
 692         goto fail;
 693     }
 694
 695     if (setup_inotify(u) < 0)
 696         goto fail;
 697
 698     if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
 699         pa_log("Failed to initialize monitor.");
 700         goto fail;
 701     }
 702
 703     if (udev_monitor_filter_add_match_subsystem_devtype(u->monitor, "sound", NULL) < 0) {
 704         pa_log("Failed to subscribe to sound devices.");
 705         goto fail;
 706     }
 707
 708     errno = 0;
 709     if (udev_monitor_enable_receiving(u->monitor) < 0) {
 710         pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
 711         if (errno == EPERM)
 712             pa_log_info("Most likely your kernel is simply too old and "
 713                         "allows only priviliged processes to listen to device events. "
 714                         "Please upgrade your kernel to at least 2.6.30.");
 715         goto fail;
 716     }
 717
 718     if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
 719         pa_log("Failed to get udev monitor fd.");
 720         goto fail;
 721     }
 722
 723     pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
 724
 725     if (!(enumerate = udev_enumerate_new(u->udev))) {
 726         pa_log("Failed to initialize udev enumerator.");
 727         goto fail;
 728     }
 729
 730     if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
 731         pa_log("Failed to match to subsystem.");
 732         goto fail;
 733     }
 734
 735     if (udev_enumerate_scan_devices(enumerate) < 0) {
 736         pa_log("Failed to scan for devices.");
 737         goto fail;
 738     }
 739
 740     first = udev_enumerate_get_list_entry(enumerate);
 741     udev_list_entry_foreach(item, first)
 742         process_path(u, udev_list_entry_get_name(item));
 743
 744     udev_enumerate_unref(enumerate);
 745
 746     pa_log_info("Found %u cards.", pa_hashmap_size(u->devices));
 747
 748     pa_modargs_free(ma);
 749
 750     return 0;
 751
 752 fail:
 753
 754     if (enumerate)
 755         udev_enumerate_unref(enumerate);
 756
 757     if (ma)
 758         pa_modargs_free(ma);
 759
 760     pa__done(m);
 761
 762     return -1;
 763 }
 764
 765 void pa__done(pa_module *m) {
 766     struct userdata *u;
 767
 768     pa_assert(m);
 769
 770     if (!(u = m->userdata))
 771         return;
 772
 773     if (u->udev_io)
 774         m->core->mainloop->io_free(u->udev_io);
 775
 776     if (u->monitor)
 777         udev_monitor_unref(u->monitor);
 778
 779     if (u->udev)
 780         udev_unref(u->udev);
 781
 782     if (u->inotify_io)
 783         m->core->mainloop->io_free(u->inotify_io);
 784
 785     if (u->inotify_fd >= 0)
 786         pa_close(u->inotify_fd);
 787
 788     if (u->devices) {
 789         struct device *d;
 790
 791         while ((d = pa_hashmap_steal_first(u->devices)))
 792             device_free(d);
 793
 794         pa_hashmap_free(u->devices, NULL, NULL);
 795     }
 796
 797     pa_xfree(u);
 798 }