[ALSA] Use posix clock monotonic for PCM and timer timestamps
We need an accurate and continuous (monotonic) time sources to do
accurate synchronization among more timing sources. This patch allows
to enable monotonic timestamps for ALSA PCM devices and enables monotonic
timestamps for ALSA timer devices.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 6245bda..cdeae7c 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -598,9 +598,9 @@
if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_MMAP)
status->tstamp = runtime->status->tstamp;
else
- getnstimeofday(&status->tstamp);
+ snd_pcm_gettime(runtime, &status->tstamp);
} else
- getnstimeofday(&status->tstamp);
+ snd_pcm_gettime(runtime, &status->tstamp);
status->appl_ptr = runtime->control->appl_ptr;
status->hw_ptr = runtime->status->hw_ptr;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
@@ -688,7 +688,7 @@
if (runtime->trigger_master == NULL)
return;
if (runtime->trigger_master == substream) {
- getnstimeofday(&runtime->trigger_tstamp);
+ snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
} else {
snd_pcm_trigger_tstamp(runtime->trigger_master);
runtime->trigger_tstamp = runtime->trigger_master->runtime->trigger_tstamp;
@@ -2519,6 +2519,21 @@
return -EFAULT;
return 0;
}
+
+static int snd_pcm_tstamp(struct snd_pcm_substream *substream, int __user *_arg)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ int arg;
+
+ if (get_user(arg, _arg))
+ return -EFAULT;
+ if (arg < 0 || arg > SNDRV_PCM_TSTAMP_TYPE_LAST)
+ return -EINVAL;
+ runtime->tstamp_type = SNDRV_PCM_TSTAMP_TYPE_GETTIMEOFDAY;
+ if (arg == SNDRV_PCM_TSTAMP_TYPE_MONOTONIC)
+ runtime->tstamp_type = SNDRV_PCM_TSTAMP_TYPE_MONOTONIC;
+ return 0;
+}
static int snd_pcm_common_ioctl1(struct file *file,
struct snd_pcm_substream *substream,
@@ -2531,8 +2546,8 @@
return put_user(SNDRV_PCM_VERSION, (int __user *)arg) ? -EFAULT : 0;
case SNDRV_PCM_IOCTL_INFO:
return snd_pcm_info_user(substream, arg);
- case SNDRV_PCM_IOCTL_TSTAMP: /* just for compatibility */
- return 0;
+ case SNDRV_PCM_IOCTL_TTSTAMP:
+ return snd_pcm_tstamp(substream, arg);
case SNDRV_PCM_IOCTL_HW_REFINE:
return snd_pcm_hw_refine_user(substream, arg);
case SNDRV_PCM_IOCTL_HW_PARAMS: