From 195ea5920975dd6136add9bf2b5e2e1151fa517e Mon Sep 17 00:00:00 2001
From: Andrew Kelley <superjoe30@gmail.com>
Date: Wed, 26 Aug 2015 12:30:46 -0700
Subject: [PATCH] ALSA: fix playback on raw device

---
 README.md          |  1 -
 example/sio_sine.c |  5 +++++
 src/alsa.cpp       | 29 ++++++++++++++++++-----------
 src/alsa.hpp       |  1 +
 4 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 23d58f7..857d1c6 100644
--- a/README.md
+++ b/README.md
@@ -274,7 +274,6 @@ Then look at `html/index.html` in a browser.
 
 ## Roadmap
 
- 0. test sio_sine with ALSA raw device
  0. Make sure PulseAudio can handle refresh devices crashing before
     block_until_have_devices
  0. Integrate into libgroove and test with Groove Basin
diff --git a/example/sio_sine.c b/example/sio_sine.c
index b75bfb5..04a56a6 100644
--- a/example/sio_sine.c
+++ b/example/sio_sine.c
@@ -188,6 +188,11 @@ int main(int argc, char **argv) {
 
     fprintf(stderr, "Output device: %s\n", device->name);
 
+    if (device->probe_error) {
+        fprintf(stderr, "Cannot probe device: %s\n", soundio_strerror(device->probe_error));
+        return 1;
+    }
+
     struct SoundIoOutStream *outstream = soundio_outstream_create(device);
     outstream->write_callback = write_callback;
     outstream->underflow_callback = underflow_callback;
diff --git a/src/alsa.cpp b/src/alsa.cpp
index cdc6c6b..a0d0389 100644
--- a/src/alsa.cpp
+++ b/src/alsa.cpp
@@ -970,6 +970,17 @@ void outstream_thread_run(void *arg) {
             }
             case SND_PCM_STATE_PREPARED:
             {
+                snd_pcm_sframes_t avail = snd_pcm_avail_update(osa->handle);
+                if (avail < 0) {
+                    outstream->error_callback(outstream, SoundIoErrorStreaming);
+                    return;
+                }
+
+                if ((snd_pcm_uframes_t)avail == osa->buffer_size_frames) {
+                    outstream->write_callback(outstream, 0, avail);
+                    continue;
+                }
+
                 if ((err = snd_pcm_start(osa->handle)) < 0) {
                     outstream->error_callback(outstream, SoundIoErrorStreaming);
                     return;
@@ -1155,6 +1166,13 @@ static int outstream_open_alsa(SoundIoPrivate *si, SoundIoOutStreamPrivate *os)
         return SoundIoErrorOpeningDevice;
     }
 
+    osa->buffer_size_frames = ceil(outstream->software_latency * (double)outstream->sample_rate);
+
+    if ((err = snd_pcm_hw_params_set_buffer_size_near(osa->handle, hwparams, &osa->buffer_size_frames)) < 0) {
+        outstream_destroy_alsa(si, os);
+        return SoundIoErrorOpeningDevice;
+    }
+    outstream->software_latency = ((double)osa->buffer_size_frames) / (double)outstream->sample_rate;
 
     if (device->is_raw) {
         unsigned int microseconds;
@@ -1172,17 +1190,6 @@ static int outstream_open_alsa(SoundIoPrivate *si, SoundIoOutStreamPrivate *os)
         }
     }
 
-
-    snd_pcm_uframes_t buffer_size_frames = ceil(outstream->software_latency * (double)outstream->sample_rate);
-
-    if ((err = snd_pcm_hw_params_set_buffer_size_near(osa->handle, hwparams, &buffer_size_frames)) < 0) {
-        outstream_destroy_alsa(si, os);
-        return SoundIoErrorOpeningDevice;
-    }
-    outstream->software_latency = ((double)buffer_size_frames) / (double)outstream->sample_rate;
-
-
-
     snd_pcm_uframes_t period_size;
     if ((snd_pcm_hw_params_get_period_size(hwparams, &period_size, nullptr)) < 0) {
         outstream_destroy_alsa(si, os);
diff --git a/src/alsa.hpp b/src/alsa.hpp
index bac9ea8..de7f874 100644
--- a/src/alsa.hpp
+++ b/src/alsa.hpp
@@ -42,6 +42,7 @@ struct SoundIoOutStreamAlsa {
     int chmap_size;
     snd_pcm_uframes_t offset;
     snd_pcm_access_t access;
+    snd_pcm_uframes_t buffer_size_frames;
     int sample_buffer_size;
     char *sample_buffer;
     int poll_fd_count;