audio: don't put output in standby when changing route

The OMAP4 ALSA kernel code can now handle output routing
changes when the PCM is opened. This avoids pops when
closing PCMs to change the route between speaker and
headset for example, and makes a noticeable difference
when notifications occur when playing music.

Change-Id: I957d96fae6764a3049d4f3c00074a9295a18d66d

1 files changed, 12 insertions, 13 deletions

diff --git a/audio/audio_hw.c b/audio/audio_hw.c
index 1ecf92a..df90985 100644
--- a/audio/audio_hw.c
+++ b/audio/audio_hw.c
@@ -661,14 +661,7 @@ static void set_input_volumes(struct tuna_audio_device *adev, int main_mic_on,
 static void force_all_standby(struct tuna_audio_device *adev)
 {
     struct tuna_stream_in *in;
-    struct tuna_stream_out *out;
 
-    if (adev->active_output) {
-        out = adev->active_output;
-        pthread_mutex_lock(&out->lock);
-        do_output_standby(out);
-        pthread_mutex_unlock(&out->lock);
-    }
     if (adev->active_input) {
         in = adev->active_input;
         pthread_mutex_lock(&in->lock);
@@ -1146,18 +1139,16 @@ static int out_set_parameters(struct audio_stream *stream, const char *kvpairs)
         pthread_mutex_lock(&out->lock);
         if ((out->device != val) && (val != 0)) {
             out->device = val;
-            if (adev->mode == AUDIO_MODE_IN_CALL) {
-                adev->devices &= ~AUDIO_DEVICE_OUT_ALL;
-                adev->devices |= out->device;
-                select_output_device(adev);
-            } else if (out == adev->active_output) {
-                do_output_standby(out);
+            if (out == adev->active_output) {
                 /* a change in output device may change the microphone selection */
                 if (adev->active_input &&
                         adev->active_input->source == AUDIO_SOURCE_VOICE_COMMUNICATION) {
                     force_input_standby = true;
                 }
             }
+            adev->devices &= ~AUDIO_DEVICE_OUT_ALL;
+            adev->devices |= out->device;
+            select_output_device(adev);
         }
         pthread_mutex_unlock(&out->lock);
         if (force_input_standby) {
@@ -1956,6 +1947,14 @@ static int adev_open_output_stream(struct audio_hw_device *dev,
     out->dev = ladev;
     out->standby = 1;
 
+    /* FIXME: when we support multiple output devices, we will want to
+     * do the following:
+     * adev->devices &= ~AUDIO_DEVICE_OUT_ALL;
+     * adev->devices |= out->device;
+     * select_output_device(adev);
+     * This is because out_set_parameters() with a route is not
+     * guaranteed to be called after an output stream is opened. */
+
     *format = out_get_format(&out->stream.common);
     *channels = out_get_channels(&out->stream.common);
     *sample_rate = out_get_sample_rate(&out->stream.common);