2 This file is part of PulseAudio.
4 Copyright 2009 Lennart Poettering
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.
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.
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
29 #include <sys/inotify.h>
32 #include <pulse/timeval.h>
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>
40 #include "module-udev-detect-symdef.h"
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);
47 "tsched=<enable system timer based scheduling mode?> "
48 "ignore_dB=<ignore dB information from the device?>");
52 pa_bool_t need_verify;
56 pa_ratelimit ratelimit;
63 pa_bool_t use_tsched:1;
64 pa_bool_t ignore_dB:1;
67 struct udev_monitor *monitor;
71 pa_io_event *inotify_io;
74 static const char* const valid_modargs[] = {
80 static int setup_inotify(struct userdata *u);
82 static void device_free(struct device *d) {
86 pa_xfree(d->card_name);
91 static const char *path_get_card_id(const char *path) {
97 if (!(e = strrchr(path, '/')))
100 if (!pa_startswith(e, "/card"))
106 static pa_bool_t is_card_busy(const char *id) {
107 char *card_path = NULL, *pcm_path = NULL, *sub_status = NULL;
108 DIR *card_dir = NULL, *pcm_dir = NULL;
109 FILE *status_file = NULL;
111 struct dirent *space = NULL, *de;
112 pa_bool_t busy = FALSE;
117 /* This simply uses /proc/asound/card.../pcm.../sub.../status to
118 * check whether there is still a process using this audio device. */
120 card_path = pa_sprintf_malloc("/proc/asound/card%s", id);
122 if (!(card_dir = opendir(card_path))) {
123 pa_log_warn("Failed to open %s: %s", card_path, pa_cstrerror(errno));
127 len = offsetof(struct dirent, d_name) + fpathconf(dirfd(card_dir), _PC_NAME_MAX) + 1;
128 space = pa_xmalloc(len);
133 if ((r = readdir_r(card_dir, space, &de)) != 0) {
134 pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
141 if (!pa_startswith(de->d_name, "pcm"))
145 pcm_path = pa_sprintf_malloc("%s/%s", card_path, de->d_name);
150 if (!(pcm_dir = opendir(pcm_path))) {
151 pa_log_warn("Failed to open %s: %s", pcm_path, pa_cstrerror(errno));
158 if ((r = readdir_r(pcm_dir, space, &de)) != 0) {
159 pa_log_warn("readdir_r() failed: %s", pa_cstrerror(r));
166 if (!pa_startswith(de->d_name, "sub"))
169 pa_xfree(sub_status);
170 sub_status = pa_sprintf_malloc("%s/%s/status", pcm_path, de->d_name);
175 if (!(status_file = pa_fopen_cloexec(sub_status, "r"))) {
176 pa_log_warn("Failed to open %s: %s", sub_status, pa_cstrerror(errno));
180 if (!(fgets(line, sizeof(line)-1, status_file))) {
181 pa_log_warn("Failed to read from %s: %s", sub_status, pa_cstrerror(errno));
185 if (!pa_streq(line, "closed\n")) {
196 pa_xfree(sub_status);
211 static void verify_access(struct userdata *u, struct device *d) {
214 pa_bool_t accessible;
219 cd = pa_sprintf_malloc("%s/snd/controlC%s", udev_get_dev_path(u->udev), path_get_card_id(d->path));
220 accessible = access(cd, R_OK|W_OK) >= 0;
221 pa_log_debug("%s is accessible: %s", cd, pa_yes_no(accessible));
225 if (d->module == PA_INVALID_INDEX) {
227 /* If we are not loaded, try to load */
233 /* Check if any of the PCM devices that belong to this
234 * card are currently busy. If they are, don't try to load
235 * right now, to make sure the probing phase can
236 * successfully complete. When the current user of the
237 * device closes it we will get another notification via
238 * inotify and can then recheck. */
240 busy = is_card_busy(path_get_card_id(d->path));
241 pa_log_debug("%s is busy: %s", d->path, pa_yes_no(busy));
245 /* So, why do we rate limit here? It's certainly ugly,
246 * but there seems to be no other way. Problem is
247 * this: if we are unable to configure/probe an audio
248 * device after opening it we will close it again and
249 * the module initialization will fail. This will then
250 * cause an inotify event on the device node which
251 * will be forwarded to us. We then try to reopen the
252 * audio device again, practically entering a busy
255 * A clean fix would be if we would be able to ignore
256 * our own inotify close events. However, inotify
257 * lacks such functionality. Also, during probing of
258 * the device we cannot really distuingish between
259 * other processes causing EBUSY or ourselves, which
260 * means we have no way to figure out if the probing
261 * during opening was canceled by a "try again"
262 * failure or a "fatal" failure. */
264 if (pa_ratelimit_test(&d->ratelimit)) {
265 pa_log_debug("Loading module-alsa-card with arguments '%s'", d->args);
266 m = pa_module_load(u->core, "module-alsa-card", d->args);
269 d->module = m->index;
270 pa_log_info("Card %s (%s) module loaded.", d->path, d->card_name);
272 pa_log_info("Card %s (%s) failed to load module.", d->path, d->card_name);
274 pa_log_warn("Tried to configure %s (%s) more often than %u times in %llus",
278 (long long unsigned) (d->ratelimit.interval / PA_USEC_PER_SEC));
284 /* If we are already loaded update suspend status with
285 * accessible boolean */
287 if ((card = pa_namereg_get(u->core, d->card_name, PA_NAMEREG_CARD)))
288 pa_card_suspend(card, !accessible, PA_SUSPEND_SESSION);
292 static void card_changed(struct userdata *u, struct udev_device *dev) {
301 /* Maybe /dev/snd is now available? */
304 path = udev_device_get_devpath(dev);
306 if ((d = pa_hashmap_get(u->devices, path))) {
311 d = pa_xnew0(struct device, 1);
312 d->path = pa_xstrdup(path);
313 d->module = PA_INVALID_INDEX;
314 PA_INIT_RATELIMIT(d->ratelimit, 10*PA_USEC_PER_SEC, 5);
316 if (!(t = udev_device_get_property_value(dev, "PULSE_NAME")))
317 if (!(t = udev_device_get_property_value(dev, "ID_ID")))
318 if (!(t = udev_device_get_property_value(dev, "ID_PATH")))
319 t = path_get_card_id(path);
321 n = pa_namereg_make_valid_name(t);
322 d->card_name = pa_sprintf_malloc("alsa_card.%s", n);
323 d->args = pa_sprintf_malloc("device_id=\"%s\" "
328 "card_properties=\"module-udev-detect.discovered=1\"",
329 path_get_card_id(path),
332 pa_yes_no(u->use_tsched),
333 pa_yes_no(u->ignore_dB));
336 pa_hashmap_put(u->devices, d->path, d);
341 static void remove_card(struct userdata *u, struct udev_device *dev) {
347 if (!(d = pa_hashmap_remove(u->devices, udev_device_get_devpath(dev))))
350 pa_log_info("Card %s removed.", d->path);
352 if (d->module != PA_INVALID_INDEX)
353 pa_module_unload_request_by_index(u->core, d->module, TRUE);
358 static void process_device(struct userdata *u, struct udev_device *dev) {
359 const char *action, *ff;
364 if (udev_device_get_property_value(dev, "PULSE_IGNORE")) {
365 pa_log_debug("Ignoring %s, because marked so.", udev_device_get_devpath(dev));
369 if ((ff = udev_device_get_property_value(dev, "SOUND_CLASS")) &&
370 pa_streq(ff, "modem")) {
371 pa_log_debug("Ignoring %s, because it is a modem.", udev_device_get_devpath(dev));
375 action = udev_device_get_action(dev);
377 if (action && pa_streq(action, "remove"))
379 else if ((!action || pa_streq(action, "change")) &&
380 udev_device_get_property_value(dev, "SOUND_INITIALIZED"))
381 card_changed(u, dev);
383 /* For an explanation why we don't look for 'add' events here
384 * have a look into /lib/udev/rules.d/78-sound-card.rules! */
387 static void process_path(struct userdata *u, const char *path) {
388 struct udev_device *dev;
390 if (!path_get_card_id(path))
393 if (!(dev = udev_device_new_from_syspath(u->udev, path))) {
394 pa_log("Failed to get udev device object from udev.");
398 process_device(u, dev);
399 udev_device_unref(dev);
402 static void monitor_cb(
406 pa_io_event_flags_t events,
409 struct userdata *u = userdata;
410 struct udev_device *dev;
414 if (!(dev = udev_monitor_receive_device(u->monitor))) {
415 pa_log("Failed to get udev device object from monitor.");
419 if (!path_get_card_id(udev_device_get_devpath(dev))) {
420 udev_device_unref(dev);
424 process_device(u, dev);
425 udev_device_unref(dev);
429 a->io_free(u->udev_io);
433 static pa_bool_t pcm_node_belongs_to_device(
440 cd = pa_sprintf_malloc("pcmC%sD", path_get_card_id(d->path));
441 b = pa_startswith(node, cd);
447 static pa_bool_t control_node_belongs_to_device(
454 cd = pa_sprintf_malloc("controlC%s", path_get_card_id(d->path));
455 b = pa_streq(node, cd);
461 static void inotify_cb(
465 pa_io_event_flags_t events,
469 struct inotify_event e;
472 struct userdata *u = userdata;
474 pa_bool_t deleted = FALSE;
480 struct inotify_event *event;
483 if ((r = pa_read(fd, &buf, sizeof(buf), &type)) <= 0) {
485 if (r < 0 && errno == EAGAIN)
488 pa_log("read() from inotify failed: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
496 if ((size_t) r < sizeof(struct inotify_event)) {
497 pa_log("read() too short.");
501 len = sizeof(struct inotify_event) + event->len;
503 if ((size_t) r < len) {
504 pa_log("Payload missing.");
508 /* From udev we get the guarantee that the control
509 * device's ACL is changed last. To avoid races when ACLs
510 * are changed we hence watch only the control device */
511 if (((event->mask & IN_ATTRIB) && pa_startswith(event->name, "controlC")))
512 PA_HASHMAP_FOREACH(d, u->devices, state)
513 if (control_node_belongs_to_device(d, event->name))
514 d->need_verify = TRUE;
516 /* ALSA doesn't really give us any guarantee on the closing
517 * order, so let's simply hope */
518 if (((event->mask & IN_CLOSE_WRITE) && pa_startswith(event->name, "pcmC")))
519 PA_HASHMAP_FOREACH(d, u->devices, state)
520 if (pcm_node_belongs_to_device(d, event->name))
521 d->need_verify = TRUE;
523 /* /dev/snd/ might have been removed */
524 if ((event->mask & (IN_DELETE_SELF|IN_MOVE_SELF)))
527 event = (struct inotify_event*) ((uint8_t*) event + len);
532 PA_HASHMAP_FOREACH(d, u->devices, state)
533 if (d->need_verify) {
534 d->need_verify = FALSE;
543 a->io_free(u->inotify_io);
544 u->inotify_io = NULL;
547 if (u->inotify_fd >= 0) {
548 pa_close(u->inotify_fd);
553 static int setup_inotify(struct userdata *u) {
557 if (u->inotify_fd >= 0)
560 if ((u->inotify_fd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) {
561 pa_log("inotify_init1() failed: %s", pa_cstrerror(errno));
565 dev_snd = pa_sprintf_malloc("%s/snd", udev_get_dev_path(u->udev));
566 r = inotify_add_watch(u->inotify_fd, dev_snd, IN_ATTRIB|IN_CLOSE_WRITE|IN_DELETE_SELF|IN_MOVE_SELF);
570 int saved_errno = errno;
572 pa_close(u->inotify_fd);
575 if (saved_errno == ENOENT) {
576 pa_log_debug("/dev/snd/ is apparently not existing yet, retrying to create inotify watch later.");
580 if (saved_errno == ENOSPC) {
581 pa_log("You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. "
582 "I wished people would do their homework first and fix inotify before using it for watching whole "
583 "directory trees which is something the current inotify is certainly not useful for. "
584 "Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.");
588 pa_log("inotify_add_watch() failed: %s", pa_cstrerror(saved_errno));
592 pa_assert_se(u->inotify_io = u->core->mainloop->io_new(u->core->mainloop, u->inotify_fd, PA_IO_EVENT_INPUT, inotify_cb, u));
597 int pa__init(pa_module *m) {
598 struct userdata *u = NULL;
600 struct udev_enumerate *enumerate = NULL;
601 struct udev_list_entry *item = NULL, *first = NULL;
603 pa_bool_t use_tsched = TRUE, ignore_dB = FALSE;
607 if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
608 pa_log("Failed to parse module arguments");
612 m->userdata = u = pa_xnew0(struct userdata, 1);
614 u->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
617 if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
618 pa_log("Failed to parse tsched= argument.");
621 u->use_tsched = use_tsched;
623 if (pa_modargs_get_value_boolean(ma, "ignore_dB", &ignore_dB) < 0) {
624 pa_log("Failed to parse ignore_dB= argument.");
627 u->ignore_dB = ignore_dB;
629 if (!(u->udev = udev_new())) {
630 pa_log("Failed to initialize udev library.");
634 if (setup_inotify(u) < 0)
637 if (!(u->monitor = udev_monitor_new_from_netlink(u->udev, "udev"))) {
638 pa_log("Failed to initialize monitor.");
642 if (udev_monitor_filter_add_match_subsystem_devtype(u->monitor, "sound", NULL) < 0) {
643 pa_log("Failed to subscribe to sound devices.");
648 if (udev_monitor_enable_receiving(u->monitor) < 0) {
649 pa_log("Failed to enable monitor: %s", pa_cstrerror(errno));
651 pa_log_info("Most likely your kernel is simply too old and "
652 "allows only priviliged processes to listen to device events. "
653 "Please upgrade your kernel to at least 2.6.30.");
657 if ((fd = udev_monitor_get_fd(u->monitor)) < 0) {
658 pa_log("Failed to get udev monitor fd.");
662 pa_assert_se(u->udev_io = u->core->mainloop->io_new(u->core->mainloop, fd, PA_IO_EVENT_INPUT, monitor_cb, u));
664 if (!(enumerate = udev_enumerate_new(u->udev))) {
665 pa_log("Failed to initialize udev enumerator.");
669 if (udev_enumerate_add_match_subsystem(enumerate, "sound") < 0) {
670 pa_log("Failed to match to subsystem.");
674 if (udev_enumerate_scan_devices(enumerate) < 0) {
675 pa_log("Failed to scan for devices.");
679 first = udev_enumerate_get_list_entry(enumerate);
680 udev_list_entry_foreach(item, first)
681 process_path(u, udev_list_entry_get_name(item));
683 udev_enumerate_unref(enumerate);
685 pa_log_info("Found %u cards.", pa_hashmap_size(u->devices));
694 udev_enumerate_unref(enumerate);
704 void pa__done(pa_module *m) {
709 if (!(u = m->userdata))
713 m->core->mainloop->io_free(u->udev_io);
716 udev_monitor_unref(u->monitor);
722 m->core->mainloop->io_free(u->inotify_io);
724 if (u->inotify_fd >= 0)
725 pa_close(u->inotify_fd);
730 while ((d = pa_hashmap_steal_first(u->devices)))
733 pa_hashmap_free(u->devices, NULL, NULL);