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authorJaroslav Kysela <perex@perex.cz>2007-12-13 10:19:42 +0100
committerJaroslav Kysela <perex@perex.cz>2008-01-31 17:29:31 +0100
commitb751eef1fdffca5532344285f2fad0c60d2f0158 (patch)
treed504104c6315a8abc4b3f657f8f4828fb55a8795 /sound/core
parent25543fa785a32ce22e7374ba403eb6d38854d037 (diff)
[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>
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/pcm_lib.c2
-rw-r--r--sound/core/pcm_native.c25
-rw-r--r--sound/core/timer.c16
3 files changed, 34 insertions, 9 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 93d7ca50273..db3d7e934ec 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -188,7 +188,7 @@ static inline int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *subs
snd_pcm_sframes_t delta;
if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_MMAP)
- getnstimeofday((struct timespec *)&runtime->status->tstamp);
+ snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
if (pos == SNDRV_PCM_POS_XRUN) {
xrun(substream);
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 6245bdaffa6..cdeae7c46e3 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -598,9 +598,9 @@ int snd_pcm_status(struct snd_pcm_substream *substream,
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 @@ static void snd_pcm_trigger_tstamp(struct snd_pcm_substream *substream)
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 @@ static int snd_pcm_sync_ptr(struct snd_pcm_substream *substream,
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 @@ static int snd_pcm_common_ioctl1(struct file *file,
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:
diff --git a/sound/core/timer.c b/sound/core/timer.c
index e7dc56ca4b9..7e5fe2d9166 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -44,11 +44,14 @@
#endif
static int timer_limit = DEFAULT_TIMER_LIMIT;
+static int timer_tstamp_monotonic = 1;
MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.de>");
MODULE_DESCRIPTION("ALSA timer interface");
MODULE_LICENSE("GPL");
module_param(timer_limit, int, 0444);
MODULE_PARM_DESC(timer_limit, "Maximum global timers in system.");
+module_param(timer_tstamp_monotonic, int, 0444);
+MODULE_PARM_DESC(timer_tstamp_monotonic, "Use posix monotonic clock source for timestamps (default).");
struct snd_timer_user {
struct snd_timer_instance *timeri;
@@ -381,7 +384,10 @@ static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
struct snd_timer_instance *ts;
struct timespec tstamp;
- getnstimeofday(&tstamp);
+ if (timer_tstamp_monotonic)
+ do_posix_clock_monotonic_gettime(&tstamp);
+ else
+ getnstimeofday(&tstamp);
snd_assert(event >= SNDRV_TIMER_EVENT_START &&
event <= SNDRV_TIMER_EVENT_PAUSE, return);
if (event == SNDRV_TIMER_EVENT_START ||
@@ -1182,8 +1188,12 @@ static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
spin_unlock(&tu->qlock);
return;
}
- if (tu->last_resolution != resolution || ticks > 0)
- getnstimeofday(&tstamp);
+ if (tu->last_resolution != resolution || ticks > 0) {
+ if (timer_tstamp_monotonic)
+ do_posix_clock_monotonic_gettime(&tstamp);
+ else
+ getnstimeofday(&tstamp);
+ }
if ((tu->filter & (1 << SNDRV_TIMER_EVENT_RESOLUTION)) &&
tu->last_resolution != resolution) {
r1.event = SNDRV_TIMER_EVENT_RESOLUTION;