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https://github.com/alsa-project/alsa-lib.git
synced 2025-11-04 13:30:08 -05:00
pcm: Remove home brew atomic operations
We've had a few home brew atomic operations in a couple of places in the PCM code. This was for supporting the concurrent accesses, but in practice, it couldn't cover the race properly by itself alone. Since we have a wider concurrency protection via mutex now, we can get rid of these atomic codes, which worsens the portability significantly. Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai
parent
54931e5a54
commit
7a8a1d1552
7 changed files with 20 additions and 305 deletions
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@ -133,7 +133,6 @@ void snd_pcm_plugin_init(snd_pcm_plugin_t *plugin)
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memset(plugin, 0, sizeof(snd_pcm_plugin_t));
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plugin->undo_read = snd_pcm_plugin_undo_read;
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plugin->undo_write = snd_pcm_plugin_undo_write;
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snd_atomic_write_init(&plugin->watom);
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}
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static int snd_pcm_plugin_delay(snd_pcm_t *pcm, snd_pcm_sframes_t *delayp)
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@ -157,15 +156,11 @@ static int snd_pcm_plugin_prepare(snd_pcm_t *pcm)
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{
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snd_pcm_plugin_t *plugin = pcm->private_data;
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int err;
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snd_atomic_write_begin(&plugin->watom);
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err = snd_pcm_prepare(plugin->gen.slave);
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if (err < 0) {
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snd_atomic_write_end(&plugin->watom);
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if (err < 0)
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return err;
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}
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*pcm->hw.ptr = 0;
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*pcm->appl.ptr = 0;
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snd_atomic_write_end(&plugin->watom);
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if (plugin->init) {
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err = plugin->init(pcm);
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if (err < 0)
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@ -178,15 +173,11 @@ static int snd_pcm_plugin_reset(snd_pcm_t *pcm)
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{
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snd_pcm_plugin_t *plugin = pcm->private_data;
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int err;
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snd_atomic_write_begin(&plugin->watom);
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err = snd_pcm_reset(plugin->gen.slave);
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if (err < 0) {
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snd_atomic_write_end(&plugin->watom);
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if (err < 0)
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return err;
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}
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*pcm->hw.ptr = 0;
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*pcm->appl.ptr = 0;
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snd_atomic_write_end(&plugin->watom);
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if (plugin->init) {
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err = plugin->init(pcm);
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if (err < 0)
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@ -212,14 +203,10 @@ snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames
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return 0;
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sframes = frames;
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snd_atomic_write_begin(&plugin->watom);
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sframes = snd_pcm_rewind(plugin->gen.slave, sframes);
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if (sframes < 0) {
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snd_atomic_write_end(&plugin->watom);
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if (sframes < 0)
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return sframes;
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}
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snd_pcm_mmap_appl_backward(pcm, (snd_pcm_uframes_t) sframes);
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snd_atomic_write_end(&plugin->watom);
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return (snd_pcm_sframes_t) sframes;
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}
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@ -240,14 +227,10 @@ snd_pcm_sframes_t snd_pcm_plugin_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frame
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return 0;
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sframes = frames;
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snd_atomic_write_begin(&plugin->watom);
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sframes = INTERNAL(snd_pcm_forward)(plugin->gen.slave, sframes);
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if (sframes < 0) {
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snd_atomic_write_end(&plugin->watom);
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if (sframes < 0)
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return sframes;
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}
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snd_pcm_mmap_appl_forward(pcm, (snd_pcm_uframes_t) frames);
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snd_atomic_write_end(&plugin->watom);
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return (snd_pcm_sframes_t) frames;
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}
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@ -279,31 +262,27 @@ static snd_pcm_sframes_t snd_pcm_plugin_write_areas(snd_pcm_t *pcm,
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err = -EPIPE;
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goto error;
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}
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snd_atomic_write_begin(&plugin->watom);
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result = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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if (result > 0 && (snd_pcm_uframes_t)result != slave_frames) {
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snd_pcm_sframes_t res;
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res = plugin->undo_write(pcm, slave_areas, slave_offset + result, slave_frames, slave_frames - result);
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if (res < 0) {
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err = res;
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goto error_atomic;
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goto error;
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}
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frames -= res;
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}
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if (result <= 0) {
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err = result;
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goto error_atomic;
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goto error;
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}
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snd_pcm_mmap_appl_forward(pcm, frames);
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snd_atomic_write_end(&plugin->watom);
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offset += frames;
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xfer += frames;
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size -= frames;
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}
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return (snd_pcm_sframes_t)xfer;
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error_atomic:
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snd_atomic_write_end(&plugin->watom);
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error:
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return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
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}
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@ -336,7 +315,6 @@ static snd_pcm_sframes_t snd_pcm_plugin_read_areas(snd_pcm_t *pcm,
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err = -EPIPE;
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goto error;
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}
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snd_atomic_write_begin(&plugin->watom);
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result = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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if (result > 0 && (snd_pcm_uframes_t)result != slave_frames) {
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snd_pcm_sframes_t res;
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@ -344,24 +322,21 @@ static snd_pcm_sframes_t snd_pcm_plugin_read_areas(snd_pcm_t *pcm,
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res = plugin->undo_read(slave, areas, offset, frames, slave_frames - result);
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if (res < 0) {
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err = res;
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goto error_atomic;
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goto error;
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}
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frames -= res;
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}
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if (result <= 0) {
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err = result;
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goto error_atomic;
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goto error;
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}
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snd_pcm_mmap_appl_forward(pcm, frames);
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snd_atomic_write_end(&plugin->watom);
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offset += frames;
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xfer += frames;
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size -= frames;
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}
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return (snd_pcm_sframes_t)xfer;
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error_atomic:
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snd_atomic_write_end(&plugin->watom);
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error:
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return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
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}
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@ -417,9 +392,7 @@ snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
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int err;
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if (pcm->stream == SND_PCM_STREAM_CAPTURE) {
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snd_atomic_write_begin(&plugin->watom);
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snd_pcm_mmap_appl_forward(pcm, size);
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snd_atomic_write_end(&plugin->watom);
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return size;
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}
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slave_size = snd_pcm_avail_update(slave);
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@ -443,7 +416,6 @@ snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
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frames = cont;
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frames = plugin->write(pcm, areas, appl_offset, frames,
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slave_areas, slave_offset, &slave_frames);
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snd_atomic_write_begin(&plugin->watom);
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result = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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if (result > 0 && (snd_pcm_uframes_t)result != slave_frames) {
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snd_pcm_sframes_t res;
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@ -451,16 +423,15 @@ snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
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res = plugin->undo_write(pcm, slave_areas, slave_offset + result, slave_frames, slave_frames - result);
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if (res < 0) {
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err = res;
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goto error_atomic;
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goto error;
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}
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frames -= res;
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}
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if (result <= 0) {
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err = result;
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goto error_atomic;
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goto error;
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}
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snd_pcm_mmap_appl_forward(pcm, frames);
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snd_atomic_write_end(&plugin->watom);
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if (frames == cont)
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appl_offset = 0;
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else
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@ -475,8 +446,6 @@ snd_pcm_plugin_mmap_commit(snd_pcm_t *pcm,
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}
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return xfer;
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error_atomic:
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snd_atomic_write_end(&plugin->watom);
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error:
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return xfer > 0 ? xfer : err;
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}
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@ -519,7 +488,6 @@ static snd_pcm_sframes_t snd_pcm_plugin_avail_update(snd_pcm_t *pcm)
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frames = cont;
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frames = (plugin->read)(pcm, areas, hw_offset, frames,
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slave_areas, slave_offset, &slave_frames);
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snd_atomic_write_begin(&plugin->watom);
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result = snd_pcm_mmap_commit(slave, slave_offset, slave_frames);
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if (result > 0 && (snd_pcm_uframes_t)result != slave_frames) {
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snd_pcm_sframes_t res;
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@ -527,16 +495,15 @@ static snd_pcm_sframes_t snd_pcm_plugin_avail_update(snd_pcm_t *pcm)
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res = plugin->undo_read(slave, areas, hw_offset, frames, slave_frames - result);
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if (res < 0) {
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err = res;
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goto error_atomic;
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goto error;
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}
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frames -= res;
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}
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if (result <= 0) {
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err = result;
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goto error_atomic;
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goto error;
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}
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snd_pcm_mmap_hw_forward(pcm, frames);
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snd_atomic_write_end(&plugin->watom);
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if (frames == cont)
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hw_offset = 0;
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else
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@ -547,8 +514,6 @@ static snd_pcm_sframes_t snd_pcm_plugin_avail_update(snd_pcm_t *pcm)
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}
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return (snd_pcm_sframes_t)xfer;
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error_atomic:
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snd_atomic_write_end(&plugin->watom);
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error:
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return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
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}
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@ -558,24 +523,15 @@ static int snd_pcm_plugin_status(snd_pcm_t *pcm, snd_pcm_status_t * status)
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{
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snd_pcm_plugin_t *plugin = pcm->private_data;
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snd_pcm_sframes_t err;
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snd_atomic_read_t ratom;
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snd_atomic_read_init(&ratom, &plugin->watom);
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_again:
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snd_atomic_read_begin(&ratom);
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/* sync with the latest hw and appl ptrs */
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snd_pcm_plugin_avail_update(pcm);
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err = snd_pcm_status(plugin->gen.slave, status);
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if (err < 0) {
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snd_atomic_read_ok(&ratom);
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if (err < 0)
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return err;
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}
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status->appl_ptr = *pcm->appl.ptr;
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status->hw_ptr = *pcm->hw.ptr;
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if (!snd_atomic_read_ok(&ratom)) {
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snd_atomic_read_wait(&ratom);
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goto _again;
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}
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return 0;
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}
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