[ALSA] Fix PCM MMAP time-stamp mode

When MMAP time-stamp mode is given, it's supposed to update the time-stamp
only at period boundary.  However, it currently updates at each status call
so this is just useless.  The patch fixes this misbehavior.
Also it fixes the wrong check of tstamp_mode (don't use bit-and for enum).

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/core/pcm_lib.c

@@ -148,8 +148,6 @@ static inline snd_pcm_uframes_t snd_pcm_update_hw_ptr_pos(struct snd_pcm_substre
 	pos = substream->ops->pointer(substream);
 	if (pos == SNDRV_PCM_POS_XRUN)
 		return pos; /* XRUN */
-	if (runtime->tstamp_mode & SNDRV_PCM_TSTAMP_MMAP)
-		getnstimeofday((struct timespec *)&runtime->status->tstamp);
 #ifdef CONFIG_SND_DEBUG
 	if (pos >= runtime->buffer_size) {
 		snd_printk(KERN_ERR  "BUG: stream = %i, pos = 0x%lx, buffer size = 0x%lx, period size = 0x%lx\n", substream->stream, pos, runtime->buffer_size, runtime->period_size);
@@ -189,6 +187,8 @@ static inline int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *subs
 	snd_pcm_uframes_t new_hw_ptr, hw_ptr_interrupt;
 	snd_pcm_sframes_t delta;
 
+	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_MMAP)
+		getnstimeofday((struct timespec *)&runtime->status->tstamp);
 	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
 	if (pos == SNDRV_PCM_POS_XRUN) {
 		xrun(substream);

sound/core/pcm_native.c

@@ -595,7 +595,7 @@ int snd_pcm_status(struct snd_pcm_substream *substream,
 	status->trigger_tstamp = runtime->trigger_tstamp;
 	if (snd_pcm_running(substream)) {
 		snd_pcm_update_hw_ptr(substream);
-		if (runtime->tstamp_mode & SNDRV_PCM_TSTAMP_MMAP)
+		if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_MMAP)
 			status->tstamp = runtime->status->tstamp;
 		else
 			getnstimeofday(&status->tstamp);