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authorPierre-Louis Bossart <bossart.nospam@gmail.com>2011-01-31 13:20:27 -0600
committerColin Guthrie <cguthrie@mandriva.org>2011-02-01 09:41:02 +0000
commit051d82133f0ae6a57bf66fd200bc8e3591a7d5ca (patch)
tree0d593b1a20ecd97f53fc614fd4850690ec2f6802 /src/modules/alsa
parent9498440dc67376832f6d4cc0af79498643c7c3de (diff)
alsa: disable period wakeups in tsched mode if possible
This patch reflects a new capability that Lennart was wishing for. Wish granted... Re-submitting it now that alsa-lib 1.0.24 provides additional entry points to disable period wakeups in timer-scheduling mode if hardware can work without it (HDAudio, oxygen and Intel SST). Example with standard playback on HDAudio output Before change: Top causes for wakeups: 3.8% ( 5.4) [hda_intel] <interrupt> 2.8% ( 4.0) alsa-sink After change: Top causes for wakeups: 2.3% ( 3.0) alsa-sink Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
Diffstat (limited to 'src/modules/alsa')
-rw-r--r--src/modules/alsa/alsa-util.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/src/modules/alsa/alsa-util.c b/src/modules/alsa/alsa-util.c
index 5a726ffec..786e664d3 100644
--- a/src/modules/alsa/alsa-util.c
+++ b/src/modules/alsa/alsa-util.c
@@ -251,6 +251,22 @@ int pa_alsa_set_hw_params(
if (!pa_alsa_pcm_is_hw(pcm_handle))
_use_tsched = FALSE;
+#if (SND_LIB_VERSION >= ((1<<16)|(0<<8)|24)) /* API additions in 1.0.24 */
+ if (_use_tsched) {
+
+ /* try to disable period wakeups if hardware can do so */
+ if (snd_pcm_hw_params_can_disable_period_wakeup(hwparams)) {
+
+ if (snd_pcm_hw_params_set_period_wakeup(pcm_handle, hwparams, FALSE) < 0)
+ /* don't bail, keep going with default mode with period wakeups */
+ pa_log_debug("snd_pcm_hw_params_set_period_wakeup() failed: %s", pa_alsa_strerror(ret));
+ else
+ pa_log_info("Trying to disable ALSA period wakeups, using timers only");
+ } else
+ pa_log_info("cannot disable ALSA period wakeups");
+ }
+#endif
+
if ((ret = set_format(pcm_handle, hwparams, &_ss.format)) < 0)
goto finish;
@@ -378,6 +394,18 @@ success:
goto finish;
}
+#if (SND_LIB_VERSION >= ((1<<16)|(0<<8)|24)) /* API additions in 1.0.24 */
+ if (_use_tsched) {
+ unsigned int no_wakeup;
+ /* see if period wakeups were disabled */
+ snd_pcm_hw_params_get_period_wakeup(pcm_handle, hwparams, &no_wakeup);
+ if (no_wakeup == 0)
+ pa_log_info("ALSA period wakeups disabled");
+ else
+ pa_log_info("ALSA period wakeups were not disabled");
+ }
+#endif
+
ss->rate = _ss.rate;
ss->channels = _ss.channels;
ss->format = _ss.format;