ALSA: pcm: add snd_pcm_hw_rule_noresample()

[firefly-linux-kernel-4.4.55.git] / sound / core / pcm_lib.c

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 86d0caf91b35036c1431e4ec9552a560b3deed5c..95d1e789715f13b0ae9185dc213da64728d43c76 100644 (file)
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1399,6 +1399,32 @@ int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
 
 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
 
+static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
+                                          struct snd_pcm_hw_rule *rule)
+{
+       unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
+       struct snd_interval *rate;
+
+       rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
+       return snd_interval_list(rate, 1, &base_rate, 0);
+}
+
+/**
+ * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
+ * @runtime: PCM runtime instance
+ * @base_rate: the rate at which the hardware does not resample
+ */
+int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
+                              unsigned int base_rate)
+{
+       return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
+                                  SNDRV_PCM_HW_PARAM_RATE,
+                                  snd_pcm_hw_rule_noresample_func,
+                                  (void *)(uintptr_t)base_rate,
+                                  SNDRV_PCM_HW_PARAM_RATE, -1);
+}
+EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
+
 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
                                  snd_pcm_hw_param_t var)
 {
@@ -1761,6 +1787,10 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
        snd_pcm_uframes_t avail = 0;
        long wait_time, tout;
 
+       init_waitqueue_entry(&wait, current);
+       set_current_state(TASK_INTERRUPTIBLE);
+       add_wait_queue(&runtime->tsleep, &wait);
+
        if (runtime->no_period_wakeup)
                wait_time = MAX_SCHEDULE_TIMEOUT;
        else {
@@ -1771,16 +1801,32 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
                }
                wait_time = msecs_to_jiffies(wait_time * 1000);
        }
-       init_waitqueue_entry(&wait, current);
-       add_wait_queue(&runtime->tsleep, &wait);
+
        for (;;) {
                if (signal_pending(current)) {
                        err = -ERESTARTSYS;
                        break;
                }
+
+               /*
+                * We need to check if space became available already
+                * (and thus the wakeup happened already) first to close
+                * the race of space already having become available.
+                * This check must happen after been added to the waitqueue
+                * and having current state be INTERRUPTIBLE.
+                */
+               if (is_playback)
+                       avail = snd_pcm_playback_avail(runtime);
+               else
+                       avail = snd_pcm_capture_avail(runtime);
+               if (avail >= runtime->twake)
+                       break;
                snd_pcm_stream_unlock_irq(substream);
-               tout = schedule_timeout_interruptible(wait_time);
+
+               tout = schedule_timeout(wait_time);
+
                snd_pcm_stream_lock_irq(substream);
+               set_current_state(TASK_INTERRUPTIBLE);
                switch (runtime->status->state) {
                case SNDRV_PCM_STATE_SUSPENDED:
                        err = -ESTRPIPE;
@@ -1806,14 +1852,9 @@ static int wait_for_avail(struct snd_pcm_substream *substream,
                        err = -EIO;
                        break;
                }
-               if (is_playback)
-                       avail = snd_pcm_playback_avail(runtime);
-               else
-                       avail = snd_pcm_capture_avail(runtime);
-               if (avail >= runtime->twake)
-                       break;
        }
  _endloop:
+       set_current_state(TASK_RUNNING);
        remove_wait_queue(&runtime->tsleep, &wait);
        *availp = avail;
        return err;