[pulseaudio-discuss] [PATCH 4/8] alsa-mixer: Detect and then drop pointless paths in the path set.
Colin Guthrie
colin at mageia.org
Thu Jul 7 02:55:53 PDT 2011
In order to try and avoid 'spamming' the user with port choices,
attempt to detect and remove any pointless paths in a path set. That is
any paths which are subsets of other paths.
This should solve a problem case with some USB Headsets which result in
two paths both involving the 'Speaker' element. When no 'Master' element
exists (which is quite common on head/handsets), then the first path
(analog-output) will contain the 'Speaker' in a way that completely fits
with in the use of the 'Speaker' element in the other path
(analog-output-speaker).
---
src/modules/alsa/alsa-mixer.c | 167 ++++++++++++++++++++++++++++++++++++++++
src/modules/alsa/alsa-sink.c | 3 -
src/modules/alsa/alsa-source.c | 3 -
3 files changed, 167 insertions(+), 6 deletions(-)
diff --git a/src/modules/alsa/alsa-mixer.c b/src/modules/alsa/alsa-mixer.c
index abd3bf2..842fba2 100644
--- a/src/modules/alsa/alsa-mixer.c
+++ b/src/modules/alsa/alsa-mixer.c
@@ -2873,6 +2873,166 @@ void pa_alsa_path_set_dump(pa_alsa_path_set *ps) {
pa_alsa_path_dump(p);
}
+/**
+ * Compares two elements to see if a is a subset of b
+ */
+static pa_bool_t element_is_subset(pa_alsa_element *a, pa_alsa_element *b) {
+ pa_assert(a);
+ pa_assert(b);
+
+ /* General rules:
+ * Every state is a subset of itself (with caveats for volume_limits and options)
+ * IGNORE is a subset of every other state */
+
+ /* Check the volume_use */
+ if (a->volume_use != PA_ALSA_VOLUME_IGNORE) {
+
+ /* "Constant" is subset of "Constant" only when their constant values are equal */
+ if (a->volume_use == PA_ALSA_VOLUME_CONSTANT && b->volume_use == PA_ALSA_VOLUME_CONSTANT && a->constant_volume != b->constant_volume)
+ return FALSE;
+
+ /* "Constant" is a subset of "Merge", if there is not a "volume-limit" in "Merge" below the actual constant.
+ * "Zero" and "Off" are just special cases of "Constant" when comparing to "Merge"
+ * "Merge" with a "volume-limit" is a subset of "Merge" without a "volume-limit" or with a higher "volume-limit".
+ * "Zero" is a subset of "Off" */
+ if (a->volume_use != b->volume_use || b->volume_use == PA_ALSA_VOLUME_MERGE) {
+ if (a->volume_use == PA_ALSA_VOLUME_OFF && b->volume_use == PA_ALSA_VOLUME_ZERO)
+ return FALSE;
+
+ if (b->volume_use == PA_ALSA_VOLUME_MERGE && b->volume_limit >= 0) {
+ long a_limit = -1;
+ if (a->volume_use == PA_ALSA_VOLUME_CONSTANT)
+ a_limit = a->constant_volume;
+ else if (a->volume_use == PA_ALSA_VOLUME_ZERO || a->volume_use == PA_ALSA_VOLUME_OFF)
+ a_limit = 0;
+ else if (a->volume_use == PA_ALSA_VOLUME_MERGE)
+ a_limit = a->volume_limit;
+
+ if (a_limit < 0 || a_limit > b->volume_limit)
+ return FALSE;
+ }
+ }
+ }
+
+ if (a->switch_use != PA_ALSA_SWITCH_IGNORE) {
+ /* "On" is a subset of "Mute".
+ * "Off" is a subset of "Mute".
+ * "On" is a subset of "Select", if there is an "Option:On" in B.
+ * "Off" is a subset of "Select", if there is an "Option:Off" in B.
+ * "Select" is a subset of "Select", if they have the same options (is this always true?). */
+
+ if (a->switch_use != b->switch_use) {
+
+ if (a->switch_use == PA_ALSA_SWITCH_SELECT || a->switch_use == PA_ALSA_SWITCH_MUTE
+ || b->switch_use == PA_ALSA_SWITCH_OFF || b->switch_use == PA_ALSA_SWITCH_ON)
+ return FALSE;
+
+ if (b->switch_use == PA_ALSA_SWITCH_SELECT) {
+ if (a->switch_use == PA_ALSA_SWITCH_ON) {
+ pa_alsa_option *o;
+ pa_bool_t found = FALSE;
+ PA_LLIST_FOREACH(o, b->options) {
+ if (pa_streq(o->alsa_name, "on"))
+ found = TRUE;
+ }
+ if (!found)
+ return FALSE;
+ } else if (a->switch_use == PA_ALSA_SWITCH_OFF) {
+ pa_alsa_option *o;
+ pa_bool_t found = FALSE;
+ PA_LLIST_FOREACH(o, b->options) {
+ if (pa_streq(o->alsa_name, "off"))
+ found = TRUE;
+ }
+ if (!found)
+ return FALSE;
+ }
+ }
+ } else if (a->switch_use == PA_ALSA_SWITCH_SELECT) {
+ /* Treat this like an enumeration */
+ /* If there is an option A offers that B does not, then A is not a subset of B. */
+ pa_alsa_option *oa, *ob;
+ PA_LLIST_FOREACH(oa, a->options) {
+ pa_bool_t found = FALSE;
+ PA_LLIST_FOREACH(ob, b->options) {
+ if (pa_streq(oa->alsa_name, ob->alsa_name)) {
+ found = TRUE;
+ break;
+ }
+ }
+ if (!found)
+ return FALSE;
+ }
+ }
+ }
+
+ if (a->enumeration_use != PA_ALSA_ENUMERATION_IGNORE) {
+ /* If there is an option A offers that B does not, then A is not a subset of B. */
+ pa_alsa_option *oa, *ob;
+ PA_LLIST_FOREACH(oa, a->options) {
+ pa_bool_t found = FALSE;
+ PA_LLIST_FOREACH(ob, b->options) {
+ if (pa_streq(oa->alsa_name, ob->alsa_name)) {
+ found = TRUE;
+ break;
+ }
+ }
+ if (!found)
+ return FALSE;
+ }
+ }
+
+ return TRUE;
+}
+
+static void path_set_condense(pa_alsa_path_set *ps) {
+ pa_alsa_path *p, *np;
+
+ /* If we only have one path, then don't bother */
+ if (!ps->paths || !ps->paths->next)
+ return;
+
+ for (p = ps->paths; p; p = np) {
+ pa_alsa_path *p2;
+ np = p->next;
+
+ PA_LLIST_FOREACH(p2, ps->paths) {
+ pa_alsa_element *ea, *eb;
+ pa_bool_t is_subset = TRUE;
+
+ if (p == p2)
+ continue;
+
+ /* Compare the elements of each set... */
+ pa_assert_se(ea = p->elements);
+ pa_assert_se(eb = p2->elements);
+
+ while (is_subset) {
+ if (pa_streq(ea->alsa_name, eb->alsa_name)) {
+ if (element_is_subset(ea, eb)) {
+ ea = ea->next;
+ eb = eb->next;
+ if ((ea && !eb) || (!ea && eb))
+ is_subset = FALSE;
+ else if (!ea && !eb)
+ break;
+ } else
+ is_subset = FALSE;
+
+ } else
+ is_subset = FALSE;
+ }
+
+ if (is_subset) {
+ pa_log_debug("Removing path '%s' as it is a subset of '%s'.", p->name, p2->name);
+ PA_LLIST_REMOVE(pa_alsa_path, ps->paths, p);
+ pa_alsa_path_free(p);
+ break;
+ }
+ }
+ }
+}
+
static void path_set_make_paths_unique(pa_alsa_path_set *ps) {
pa_alsa_path *p, *q;
@@ -2928,8 +3088,15 @@ void pa_alsa_path_set_probe(pa_alsa_path_set *ps, snd_mixer_t *m, pa_bool_t igno
}
}
+ pa_log_debug("Found mixer paths (before tidying):");
+ pa_alsa_path_set_dump(ps);
+
+ path_set_condense(ps);
path_set_make_paths_unique(ps);
ps->probed = TRUE;
+
+ pa_log_debug("Available mixer paths (after tidying):");
+ pa_alsa_path_set_dump(ps);
}
static void mapping_free(pa_alsa_mapping *m) {
diff --git a/src/modules/alsa/alsa-sink.c b/src/modules/alsa/alsa-sink.c
index bdcf702..d6f251d 100644
--- a/src/modules/alsa/alsa-sink.c
+++ b/src/modules/alsa/alsa-sink.c
@@ -1750,9 +1750,6 @@ static void find_mixer(struct userdata *u, pa_alsa_mapping *mapping, const char
goto fail;
pa_alsa_path_set_probe(u->mixer_path_set, u->mixer_handle, ignore_dB);
-
- pa_log_debug("Probed mixer paths:");
- pa_alsa_path_set_dump(u->mixer_path_set);
}
return;
diff --git a/src/modules/alsa/alsa-source.c b/src/modules/alsa/alsa-source.c
index 5feeec1..c2f73ed 100644
--- a/src/modules/alsa/alsa-source.c
+++ b/src/modules/alsa/alsa-source.c
@@ -1525,9 +1525,6 @@ static void find_mixer(struct userdata *u, pa_alsa_mapping *mapping, const char
goto fail;
pa_alsa_path_set_probe(u->mixer_path_set, u->mixer_handle, ignore_dB);
-
- pa_log_debug("Probed mixer paths:");
- pa_alsa_path_set_dump(u->mixer_path_set);
}
return;
--
1.7.6
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