[pulseaudio-discuss] [PATCH 05/11] alsa-mixer: Detect and then drop pointless paths in the path set.

[Colin Guthrie]

Tanu,

Does this look right for the left over bits.... I appreciate it may
actually make sense to do David's off+zero -> constant thing as it would
keep some of the comparison bit much simpler, but this is an
optimisation we can do after 1.0 is out :)

In the mean time:


diff --git a/src/modules/alsa/alsa-mixer.c b/src/modules/alsa/alsa-mixer.c
index 20e6194..9470ecf 100644
--- a/src/modules/alsa/alsa-mixer.c
+++ b/src/modules/alsa/alsa-mixer.c
@@ -2911,9 +2911,10 @@ static pa_bool_t
enumeration_is_subset(pa_alsa_option *a_options, pa_alsa_option
 /**
  *  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) {
+static pa_bool_t element_is_subset(pa_alsa_element *a, pa_alsa_element
*b, snd_mixer_t *m) {
     pa_assert(a);
     pa_assert(b);
+    pa_assert(m);

     /* General rules:
      * Every state is a subset of itself (with caveats for
volume_limits and options)
@@ -2938,10 +2939,29 @@ static pa_bool_t
element_is_subset(pa_alsa_element *a, pa_alsa_element *b) {
             if (a->volume_use == PA_ALSA_VOLUME_CONSTANT)
                 a_limit = a->constant_volume;
             else if (a->volume_use == PA_ALSA_VOLUME_ZERO) {
-                /* (tk) This is wrong.a_limit should be what
-                    snd_mixer_selem_ask_playback_dB_vol() returns, or
if a->db_fix is set,
-                    then what decibel_fix_get_step() returns. */
-                a_limit = a->min_volume;
+                long dB = 0;
+
+                if (a->db_fix) {
+                    int rounding = (a->direction ==
PA_ALSA_DIRECTION_OUTPUT ? +1 : -1);
+                    a_limit = decibel_fix_get_step(a->db_fix, &dB,
rounding);
+                } else {
+                    snd_mixer_selem_id_t *sid;
+                    snd_mixer_elem_t *me;
+
+                    SELEM_INIT(sid, a->alsa_name);
+                    if (!(me = snd_mixer_find_selem(m, sid))) {
+                        pa_log_warn("Element %s seems to have
disappeared.", a->alsa_name);
+                        return FALSE;
+                    }
+
+                    if (a->direction == PA_ALSA_DIRECTION_OUTPUT) {
+                        if (snd_mixer_selem_ask_playback_dB_vol(me, dB,
+1, &a_limit) < 0)
+                            return FALSE;
+                    } else {
+                        if (snd_mixer_selem_ask_capture_dB_vol(me, dB,
-1, &a_limit) < 0)
+                            return FALSE;
+                    }
+                }
             } else if (a->volume_use == PA_ALSA_VOLUME_OFF)
                 a_limit = a->min_volume;
             else if (a->volume_use == PA_ALSA_VOLUME_MERGE)
@@ -2988,9 +3008,12 @@ static pa_bool_t
element_is_subset(pa_alsa_element *a, pa_alsa_element *b) {
     return TRUE;
 }

-static void path_set_condense(pa_alsa_path_set *ps) {
+static void path_set_condense(pa_alsa_path_set *ps, snd_mixer_t *m) {
     pa_alsa_path *p, *np;

+    pa_assert(ps);
+    pa_assert(m);
+
     /* If we only have one path, then don't bother */
     if (!ps->paths || !ps->paths->next)
         return;
@@ -3012,7 +3035,7 @@ static void path_set_condense(pa_alsa_path_set *ps) {

             while (is_subset) {
                 if (pa_streq(ea->alsa_name, eb->alsa_name)) {
-                    if (element_is_subset(ea, eb)) {
+                    if (element_is_subset(ea, eb, m)) {
                         ea = ea->next;
                         eb = eb->next;
                         if ((ea && !eb) || (!ea && eb))
@@ -3094,7 +3117,7 @@ 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_condense(ps, m);
     path_set_make_paths_unique(ps);
     ps->probed = TRUE;



-- 

Colin Guthrie
gmane(at)colin.guthr.ie
http://colin.guthr.ie/

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