5 files changed, 39 insertions, 23 deletions

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index a4fcc9456194..2882dddfc91c 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -1111,10 +1111,16 @@ static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substrea
  *  Timer interface
  */
 
+#ifdef CONFIG_SND_PCM_TIMER
 void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream);
 void snd_pcm_timer_init(struct snd_pcm_substream *substream);
 void snd_pcm_timer_done(struct snd_pcm_substream *substream);
-
+#else
+static inline void
+snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream) {}
+static inline void snd_pcm_timer_init(struct snd_pcm_substream *substream) {}
+static inline void snd_pcm_timer_done(struct snd_pcm_substream *substream) {}
+#endif
 /**
  * snd_pcm_gettime - Fill the timespec depending on the timestamp mode
  * @runtime: PCM runtime instance
diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index 6c96feeaf01e..e3e949126a56 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -4,7 +4,7 @@ config SND_TIMER
 
 config SND_PCM
         tristate
-        select SND_TIMER
+        select SND_TIMER if SND_PCM_TIMER
 
 config SND_PCM_ELD
         bool
@@ -93,6 +93,17 @@ config SND_PCM_OSS_PLUGINS
           support conversion of channels, formats and rates. It will
           behave like most of new OSS/Free drivers in 2.4/2.6 kernels.
 
+config SND_PCM_TIMER
+        bool "PCM timer interface" if EXPERT
+        default y
+        help
+          If you disable this option, pcm timer will be inavailable, so
+          those stubs used pcm timer (e.g. dmix, dsnoop & co) may work
+          incorrectlly.
+
+          For some embedded device, we may disable it to reduce memory
+          footprint, about 20KB on x86_64 platform.
+
 config SND_SEQUENCER_OSS
         bool "OSS Sequencer API"
         depends on SND_SEQUENCER
diff --git a/sound/core/Makefile b/sound/core/Makefile
index 3354f91e003a..48ab4b8f8279 100644
--- a/sound/core/Makefile
+++ b/sound/core/Makefile
@@ -13,8 +13,9 @@ snd-$(CONFIG_SND_OSSEMUL) += sound_oss.o
 snd-$(CONFIG_SND_VMASTER) += vmaster.o
 snd-$(CONFIG_SND_JACK)    += ctljack.o jack.o
 
-snd-pcm-y := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \
+snd-pcm-y := pcm.o pcm_native.o pcm_lib.o pcm_misc.o \
                 pcm_memory.o memalloc.o
+snd-pcm-$(CONFIG_SND_PCM_TIMER) += pcm_timer.o
 snd-pcm-$(CONFIG_SND_DMA_SGBUF) += sgbuf.o
 snd-pcm-$(CONFIG_SND_PCM_ELD) += pcm_drm_eld.o
 snd-pcm-$(CONFIG_SND_PCM_IEC958) += pcm_iec958.o
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 7d45645f10ba..6dc4277937b8 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1883,8 +1883,10 @@ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
             snd_pcm_update_hw_ptr0(substream, 1) < 0)
                 goto _end;
 
+#ifdef CONFIG_SND_PCM_TIMER
         if (substream->timer_running)
                 snd_timer_interrupt(substream->timer, 1);
+#endif
  _end:
         snd_pcm_stream_unlock_irqrestore(substream, flags);
         if (runtime->transfer_ack_end)
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 139887011ba2..a8b27cdc2844 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -486,6 +486,16 @@ static void snd_pcm_set_state(struct snd_pcm_substream *substream, int state)
         snd_pcm_stream_unlock_irq(substream);
 }
 
+static inline void snd_pcm_timer_notify(struct snd_pcm_substream *substream,
+                                        int event)
+{
+#ifdef CONFIG_SND_PCM_TIMER
+        if (substream->timer)
+                snd_timer_notify(substream->timer, event,
+                                        &substream->runtime->trigger_tstamp);
+#endif
+}
+
 static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
                              struct snd_pcm_hw_params *params)
 {
@@ -1043,9 +1053,7 @@ static void snd_pcm_post_start(struct snd_pcm_substream *substream, int state)
         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
             runtime->silence_size > 0)
                 snd_pcm_playback_silence(substream, ULONG_MAX);
-        if (substream->timer)
-                snd_timer_notify(substream->timer, SNDRV_TIMER_EVENT_MSTART,
-                                 &runtime->trigger_tstamp);
+        snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSTART);
 }
 
 static struct action_ops snd_pcm_action_start = {
@@ -1093,9 +1101,7 @@ static void snd_pcm_post_stop(struct snd_pcm_substream *substream, int state)
         if (runtime->status->state != state) {
                 snd_pcm_trigger_tstamp(substream);
                 runtime->status->state = state;
-                if (substream->timer)
-                        snd_timer_notify(substream->timer, SNDRV_TIMER_EVENT_MSTOP,
-                                         &runtime->trigger_tstamp);
+                snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSTOP);
         }
         wake_up(&runtime->sleep);
         wake_up(&runtime->tsleep);
@@ -1209,18 +1215,12 @@ static void snd_pcm_post_pause(struct snd_pcm_substream *substream, int push)
         snd_pcm_trigger_tstamp(substream);
         if (push) {
                 runtime->status->state = SNDRV_PCM_STATE_PAUSED;
-                if (substream->timer)
-                        snd_timer_notify(substream->timer,
-                                         SNDRV_TIMER_EVENT_MPAUSE,
-                                         &runtime->trigger_tstamp);
+                snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MPAUSE);
                 wake_up(&runtime->sleep);
                 wake_up(&runtime->tsleep);
         } else {
                 runtime->status->state = SNDRV_PCM_STATE_RUNNING;
-                if (substream->timer)
-                        snd_timer_notify(substream->timer,
-                                         SNDRV_TIMER_EVENT_MCONTINUE,
-                                         &runtime->trigger_tstamp);
+                snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MCONTINUE);
         }
 }
 
@@ -1268,9 +1268,7 @@ static void snd_pcm_post_suspend(struct snd_pcm_substream *substream, int state)
         snd_pcm_trigger_tstamp(substream);
         runtime->status->suspended_state = runtime->status->state;
         runtime->status->state = SNDRV_PCM_STATE_SUSPENDED;
-        if (substream->timer)
-                snd_timer_notify(substream->timer, SNDRV_TIMER_EVENT_MSUSPEND,
-                                 &runtime->trigger_tstamp);
+        snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MSUSPEND);
         wake_up(&runtime->sleep);
         wake_up(&runtime->tsleep);
 }
@@ -1374,9 +1372,7 @@ static void snd_pcm_post_resume(struct snd_pcm_substream *substream, int state)
         struct snd_pcm_runtime *runtime = substream->runtime;
         snd_pcm_trigger_tstamp(substream);
         runtime->status->state = runtime->status->suspended_state;
-        if (substream->timer)
-                snd_timer_notify(substream->timer, SNDRV_TIMER_EVENT_MRESUME,
-                                 &runtime->trigger_tstamp);
+        snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MRESUME);
 }
 
 static struct action_ops snd_pcm_action_resume = {