alsa: Make alsa_open() a no-op.

Move the allocation of the private_alsa_write_data struct to
->post_select() and adjust the the check whether alsa has
been initialialized accordingly.

diff --git a/alsa_write.c b/alsa_write.c
index 3428def83076b9f8b89fc4c1e41bd0c921e54fbb..0bad21992c2537f41201a36499b5cf9129b0255e 100644 (file)
--- a/alsa_write.c
+++ b/alsa_write.c
@@ -143,9 +143,8 @@ static int alsa_init(struct private_alsa_write_data *pad,
 }
 
 /* Open an instance of the alsa writer. */
-static void alsa_open(struct writer_node *wn)
+static void alsa_open(__a_unused struct writer_node *wn)
 {
-       wn->private_data = para_calloc(sizeof(struct private_alsa_write_data));
 }
 
 static void alsa_write_pre_select(struct sched *s, struct task *t)
@@ -158,7 +157,7 @@ static void alsa_write_pre_select(struct sched *s, struct task *t)
 
        if (ret == 0)
                return;
-       if (ret < 0 || !pad->handle)
+       if (ret < 0 || !pad)
                return sched_min_delay(s);
        /*
         * Data is available to be written to the alsa handle.  Compute number
@@ -187,16 +186,16 @@ static void alsa_close(struct writer_node *wn)
        struct private_alsa_write_data *pad = wn->private_data;
        PARA_INFO_LOG("closing writer node %p\n", wn);
 
-       if (pad->handle) {
-               /*
-                * It's OK to have a blocking operation here because we already
-                * made sure that the PCM output buffer is (nearly) empty.
-                */
-               snd_pcm_nonblock(pad->handle, 0);
-               snd_pcm_drain(pad->handle);
-               snd_pcm_close(pad->handle);
-               snd_config_update_free_global();
-       }
+       if (!pad)
+               return;
+       /*
+        * It's OK to have a blocking operation here because we already made
+        * sure that the PCM output buffer is (nearly) empty.
+        */
+       snd_pcm_nonblock(pad->handle, 0);
+       snd_pcm_drain(pad->handle);
+       snd_pcm_close(pad->handle);
+       snd_config_update_free_global();
        free(pad);
 }
 
@@ -218,10 +217,10 @@ again:
                return;
        btr_merge(btrn, wn->min_iqs);
        bytes = btr_next_buffer(btrn, &data);
-       if (ret < 0 || bytes < pad->bytes_per_frame) { /* eof */
+       if (ret < 0 || bytes < wn->min_iqs) { /* eof */
                assert(btr_no_parent(btrn));
                ret = -E_ALSA_EOF;
-               if (!pad->handle)
+               if (!pad)
                        goto err;
                /* wait until pending frames are played */
                if (pad->drain_barrier.tv_sec == 0) {
@@ -234,9 +233,11 @@ again:
                        goto err;
                return;
        }
-       if (!pad->handle) {
+       if (!pad) {
                int32_t val;
 
+               pad = para_calloc(sizeof(*pad));
+               wn->private_data = pad;
                if (bytes == 0) /* no data available */
                        return;
                get_btr_sample_rate(btrn, &val);