usbaudio: send through dsp (new)

Does not seem to affect UI usability, but allowable DSP loads will vary
based on device and playback sample rate.

To-Do (someday):
- Add dedicated DSP channel
- How to apply DSP settings to above new channel? (UI)
- How to lock out timestretch from being enabled?

Change-Id: Ia24d1055340354e2c32e6008e7e2b03a8e88867d

apps/codec_thread.c

@@ -249,7 +249,7 @@ static void codec_pcmbuf_insert_callback(
         }
         else
         {
-            dsp_process(ci.dsp, &src, &dst);
+            dsp_process(ci.dsp, &src, &dst, true);
 
             if (dst.remcount > 0)
             {

apps/plugin.h

@@ -751,7 +751,7 @@ struct plugin_api {
                               unsigned int setting, intptr_t value);
     struct dsp_config * (*dsp_get_config)(unsigned int dsp_id);
     void (*dsp_process)(struct dsp_config *dsp, struct dsp_buffer *src,
-                        struct dsp_buffer *dst);
+                        struct dsp_buffer *dst, bool thread_yield);
 
     enum channel_status (*mixer_channel_status)(enum pcm_mixer_channel channel);
     const void * (*mixer_channel_get_buffer)(enum pcm_mixer_channel channel,

apps/plugins/midi/midiplay.c

@@ -444,7 +444,7 @@ static inline void synthbuf(void)
         dst.remcount = 0;
         dst.bufcount = available;
         dst.p16out = (int16_t *)outptr;
-        rb->dsp_process(dsp, &src, &dst);
+        rb->dsp_process(dsp, &src, &dst, true);
         if (dst.remcount > 0)
         {
             outptr += dst.remcount;

apps/plugins/mpegplayer/audio_thread.c

@@ -665,7 +665,7 @@ static void audio_thread(void)
             }
 
             dst.bufcount = size / (2 * sizeof (int16_t));
-            rb->dsp_process(td.dsp, &td.src, &dst);
+            rb->dsp_process(td.dsp, &td.src, &dst, true);
 
             if (dst.remcount > 0)
             {

apps/plugins/test_codec.c

@@ -230,7 +230,7 @@ static int process_dsp(const void *ch1, const void *ch2, int count)
     while (1)
     {
         int old_remcount = dst.remcount;
-        rb->dsp_process(ci.dsp, &src, &dst);
+        rb->dsp_process(ci.dsp, &src, &dst, true);
         
         if (dst.bufcount <= 0 ||
             (src.remcount <= 0 && dst.remcount <= old_remcount))

apps/rbcodecconfig.h

@@ -33,11 +33,14 @@ struct dsp_loop_context
 #endif
 };
 
-static inline void dsp_process_start(struct dsp_loop_context *ctx)
+static inline void dsp_process_start(struct dsp_loop_context *ctx, bool thread_yield)
 {
     /* At least perform one yield before starting */
     ctx->last_yield = current_tick;
-    yield();
+    if (thread_yield)
+    {
+        yield();
+    }
 #if defined(CPU_COLDFIRE)
     /* set emac unit for dsp processing, and save old macsr, we're running in
        codec thread context at this point, so can't clobber it */
@@ -46,14 +49,17 @@ static inline void dsp_process_start(struct dsp_loop_context *ctx)
 #endif
 }
 
-static inline void dsp_process_loop(struct dsp_loop_context *ctx)
+static inline void dsp_process_loop(struct dsp_loop_context *ctx, bool thread_yield)
 {
     /* Yield at least once each tick */
     long tick = current_tick;
     if (TIME_AFTER(tick, ctx->last_yield))
     {
         ctx->last_yield = tick;
-        yield();
+        if (thread_yield)
+        {
+            yield();
+        }
     }
 }
 
@@ -66,12 +72,12 @@ static inline void dsp_process_end(struct dsp_loop_context *ctx)
     (void)ctx;
 }
 
-#define DSP_PROCESS_START() \
+#define DSP_PROCESS_START(yield) \
     struct dsp_loop_context __ctx; \
-    dsp_process_start(&__ctx)
+    dsp_process_start(&__ctx, yield)
 
-#define DSP_PROCESS_LOOP() \
-    dsp_process_loop(&__ctx)
+#define DSP_PROCESS_LOOP(yield) \
+    dsp_process_loop(&__ctx, yield)
 
 #define DSP_PROCESS_END() \
     dsp_process_end(&__ctx)

apps/voice_thread.c

@@ -511,7 +511,7 @@ static enum voice_state voice_buffer_insert(struct voice_thread_data *td)
         dst.bufcount = VOICE_PCM_FRAME_COUNT;
 
         td->dst = &dst;
-        dsp_process(td->dsp, &td->src, &dst);
+        dsp_process(td->dsp, &td->src, &dst, true);
         td->dst = NULL;
 
         voice_buf_commit(dst.remcount);