alsa-ucm: Fix device conformance check

Right now this check is rejecting devices whose UCM config specifies
neither a conflicting device nor a supported device list, and accepting
devices which specify both. However, a device without neither list is
actually unrestricted, and a device with both lists is a configuration
error. Fix the check to accept the former.

Furthermore, this is missing another case where an already selected
device might have a supported devices list that doesn't have the
candidate device. Make this function also check against that, and also
make it accept devices already in the set.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Part-of: <https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/596>

1 files changed, 12 insertions, 3 deletions

diff --git a/src/modules/alsa/alsa-ucm.c b/src/modules/alsa/alsa-ucm.c
index 1936ce2bf..88baf4370 100644
--- a/src/modules/alsa/alsa-ucm.c
+++ b/src/modules/alsa/alsa-ucm.c
@@ -1226,6 +1226,9 @@ static int ucm_port_contains(const char *port_name, const char *dev_name, bool i
 }
 
 static bool devset_supports_device(pa_idxset *devices, pa_alsa_ucm_device *dev) {
+    pa_alsa_ucm_device *d;
+    uint32_t idx;
+
     pa_assert(devices);
     pa_assert(dev);
 
@@ -1233,6 +1236,10 @@ static bool devset_supports_device(pa_idxset *devices, pa_alsa_ucm_device *dev)
     if (pa_idxset_isempty(devices))
         return true;
 
+    /* Device already selected */
+    if (pa_idxset_contains(devices, dev))
+        return true;
+
     /* No conflicting device must already be selected */
     if (!pa_idxset_isdisjoint(devices, dev->conflicting_devices))
         return false;
@@ -1242,9 +1249,11 @@ static bool devset_supports_device(pa_idxset *devices, pa_alsa_ucm_device *dev)
         if (!pa_idxset_issubset(devices, dev->supported_devices))
            return false;
 
-    if (pa_idxset_isempty(dev->conflicting_devices) && pa_idxset_isempty(dev->supported_devices)) {
-        return false;
-    }
+    /* Must not be unsupported by any selected device */
+    PA_IDXSET_FOREACH(d, devices, idx)
+        if (!pa_idxset_isempty(d->supported_devices))
+            if (!pa_idxset_contains(d->supported_devices, dev))
+                return false;
 
     return true;
 }