Refactor code to fetch avail, delay and timestamp values
in a single call to snd_pcm_status().
The information reported is exactly the same as before,
however it is extracted in a more atomic manner to
improve timer-based scheduling.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.boss...@linux.intel.com>
---
src/modules/alsa/alsa-sink.c | 12 ++++--------
src/modules/alsa/alsa-source.c | 12 ++++--------
src/modules/alsa/alsa-util.c | 17 ++++++++++++-----
src/modules/alsa/alsa-util.h | 2 +-
4 files changed, 21 insertions(+), 22 deletions(-)
diff --git a/src/modules/alsa/alsa-sink.c b/src/modules/alsa/alsa-sink.c
index 544399e..e4baa1f 100644
--- a/src/modules/alsa/alsa-sink.c
+++ b/src/modules/alsa/alsa-sink.c
@@ -825,6 +825,7 @@ static void update_smoother(struct userdata *u) {
int err;
pa_usec_t now1 = 0, now2;
snd_pcm_status_t *status;
+ snd_htimestamp_t htstamp = { 0, 0 };
snd_pcm_status_alloca(&status);
@@ -833,18 +834,13 @@ static void update_smoother(struct userdata *u) {
/* Let's update the time smoother */
- if (PA_UNLIKELY((err = pa_alsa_safe_delay(u->pcm_handle, &delay, u->hwbuf_size, &u->sink->sample_spec, FALSE)) < 0)) {
+ if (PA_UNLIKELY((err = pa_alsa_safe_delay(u->pcm_handle, status, &delay, u->hwbuf_size,
&u->sink->sample_spec, FALSE)) < 0)) {
pa_log_warn("Failed to query DSP status data: %s",
pa_alsa_strerror(err));
return;
}
- if (PA_UNLIKELY((err = snd_pcm_status(u->pcm_handle, status)) < 0))
- pa_log_warn("Failed to get timestamp: %s", pa_alsa_strerror(err));
- else {
- snd_htimestamp_t htstamp = { 0, 0 };
- snd_pcm_status_get_htstamp(status, &htstamp);
- now1 = pa_timespec_load(&htstamp);
- }
+ snd_pcm_status_get_htstamp(status, &htstamp);
+ now1 = pa_timespec_load(&htstamp);
/* Hmm, if the timestamp is 0, then it wasn't set and we take the current time */
if (now1 <= 0)
diff --git a/src/modules/alsa/alsa-source.c b/src/modules/alsa/alsa-source.c
index 94d4a09..17566e7 100644
--- a/src/modules/alsa/alsa-source.c
+++ b/src/modules/alsa/alsa-source.c
@@ -767,6 +767,7 @@ static void update_smoother(struct userdata *u) {
int err;
pa_usec_t now1 = 0, now2;
snd_pcm_status_t *status;
+ snd_htimestamp_t htstamp = { 0, 0 };
snd_pcm_status_alloca(&status);
@@ -775,18 +776,13 @@ static void update_smoother(struct userdata *u) {
/* Let's update the time smoother */
- if (PA_UNLIKELY((err = pa_alsa_safe_delay(u->pcm_handle, &delay, u->hwbuf_size, &u->source->sample_spec, TRUE)) < 0)) {
+ if (PA_UNLIKELY((err = pa_alsa_safe_delay(u->pcm_handle, status, &delay, u->hwbuf_size,
&u->source->sample_spec, TRUE)) < 0)) {
pa_log_warn("Failed to get delay: %s", pa_alsa_strerror(err));
return;
}
- if (PA_UNLIKELY((err = snd_pcm_status(u->pcm_handle, status)) < 0))
- pa_log_warn("Failed to get timestamp: %s", pa_alsa_strerror(err));
- else {
- snd_htimestamp_t htstamp = { 0, 0 };
- snd_pcm_status_get_htstamp(status, &htstamp);
- now1 = pa_timespec_load(&htstamp);
- }
+ snd_pcm_status_get_htstamp(status, &htstamp);
+ now1 = pa_timespec_load(&htstamp);
/* Hmm, if the timestamp is 0, then it wasn't set and we take the current time */
if (now1 <= 0)
diff --git a/src/modules/alsa/alsa-util.c b/src/modules/alsa/alsa-util.c
index bb4e307..4a29a9a 100644
--- a/src/modules/alsa/alsa-util.c
+++ b/src/modules/alsa/alsa-util.c
@@ -1141,10 +1141,11 @@ snd_pcm_sframes_t pa_alsa_safe_avail(snd_pcm_t *pcm,
size_t hwbuf_size, const pa
return n;
}
-int pa_alsa_safe_delay(snd_pcm_t *pcm, snd_pcm_sframes_t *delay, size_t hwbuf_size, const pa_sample_spec *ss, pa_bool_t capture) {
+int pa_alsa_safe_delay(snd_pcm_t *pcm, snd_pcm_status_t *status,
snd_pcm_sframes_t *delay, size_t hwbuf_size, const pa_sample_spec *ss,
+ pa_bool_t capture) {
ssize_t k;
size_t abs_k;
- int r;
+ int err;
snd_pcm_sframes_t avail = 0;
pa_assert(pcm);
@@ -1154,10 +1155,16 @@ int pa_alsa_safe_delay(snd_pcm_t *pcm,
snd_pcm_sframes_t *delay, size_t hwbuf_si
/* Some ALSA driver expose weird bugs, let's inform the user about
* what is going on. We're going to get both the avail and delay values so
- * that we can compare and check them for capture */
+ * that we can compare and check them for capture.
+ * This is done with snd_pcm_status() which provides
+ * avail, delay and timestamp values in a single kernel call to improve
+ * timer-based scheduling */
- if ((r = snd_pcm_avail_delay(pcm, &avail, delay)) < 0)
- return r;
+ if ((err = snd_pcm_status(pcm, status)) < 0)
+ return err;
+
+ avail = snd_pcm_status_get_avail(status);
+ *delay = snd_pcm_status_get_delay(status);
k = (ssize_t) *delay * (ssize_t) pa_frame_size(ss);
diff --git a/src/modules/alsa/alsa-util.h b/src/modules/alsa/alsa-util.h
index a4beed2..236a329 100644
--- a/src/modules/alsa/alsa-util.h
+++ b/src/modules/alsa/alsa-util.h
@@ -125,7 +125,7 @@ int pa_alsa_recover_from_poll(snd_pcm_t *pcm, int revents);
pa_rtpoll_item* pa_alsa_build_pollfd(snd_pcm_t *pcm, pa_rtpoll *rtpoll);
snd_pcm_sframes_t pa_alsa_safe_avail(snd_pcm_t *pcm, size_t hwbuf_size, const pa_sample_spec *ss);
-int pa_alsa_safe_delay(snd_pcm_t *pcm, snd_pcm_sframes_t *delay, size_t
hwbuf_size, const pa_sample_spec *ss, pa_bool_t capture);
+int pa_alsa_safe_delay(snd_pcm_t *pcm, snd_pcm_status_t *status,
snd_pcm_sframes_t *delay, size_t hwbuf_size, const pa_sample_spec *ss,
pa_bool_t capture);
int pa_alsa_safe_mmap_begin(snd_pcm_t *pcm, const snd_pcm_channel_area_t
**areas, snd_pcm_uframes_t *offset, snd_pcm_uframes_t *frames, size_t
hwbuf_size, const pa_sample_spec *ss);
char *pa_alsa_get_driver_name(int card);
