Hopefully the last word on getting rid of yield_codecs loops (cut read chunk to 16kB). Sansa ata driver also didn't yield enough so buffering would starve other threads. Bump priority of audio thread to keep UI more responsive.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15724 a1c6a512-1295-4272-9138-f99709370657

apps/buffering.c

@@ -88,7 +88,7 @@
 /* default point to start buffer refill */
 #define BUFFERING_DEFAULT_WATERMARK      (1024*512)
 /* amount of data to read in one read() call */
-#define BUFFERING_DEFAULT_FILECHUNK      (1024*32)
+#define BUFFERING_DEFAULT_FILECHUNK      (1024*16)
 /* point at which the file buffer will fight for CPU time */
 #define BUFFERING_CRITICAL_LEVEL         (1024*128)
 
@@ -505,7 +505,6 @@ BUFFER SPACE MANAGEMENT
 
 update_data_counters: Updates the values in data_counters
 buffer_is_low   : Returns true if the amount of useful data in the buffer is low
-yield_codec     : Used by buffer_handle to know if it should interrupt buffering
 buffer_handle   : Buffer data for a handle
 reset_handle    : Reset write position and data buffer of a handle to its offset
 rebuffer_handle : Seek to a nonbuffered part of a handle by rebuffering the data
@@ -552,25 +551,6 @@ static inline bool buffer_is_low(void)
     return data_counters.useful < BUFFERING_CRITICAL_LEVEL;
 }
 
-/* Yield to the codec thread for as long as possible if it is in need of data.
-   Return true if the caller should break to let the buffering thread process
-   new queue events */
-static bool yield_codec(void)
-{
-    if (!queue_empty(&buffering_queue))
-        return true;
-
-    while (pcmbuf_is_lowdata() && !buffer_is_low())
-    {
-        sleep(2);
-
-        if (!queue_empty(&buffering_queue))
-            return true;
-    }
-
-    return false;
-}
-
 /* Buffer data for the given handle.
    Return whether or not the buffering should continue explicitly.  */
 static bool buffer_handle(int handle_id)
@@ -653,15 +633,19 @@ static bool buffer_handle(int handle_id)
         h->available += rc;
         h->filerem -= rc;
 
-#ifdef SIMULATOR
-        sleep(1);
-#else
-        yield();
-#endif
-
         /* If this is a large file, see if we need to break or give the codec
          * more time */
-        if (h->type == TYPE_PACKET_AUDIO && yield_codec())
+        if (h->type == TYPE_PACKET_AUDIO &&
+            pcmbuf_is_lowdata() && !buffer_is_low())
+        {
+            sleep(1);
+        }
+        else
+        {
+            yield();
+        }
+
+        if (!queue_empty(&buffering_queue))
             break;
     }
 

apps/playback.c

@@ -2574,7 +2574,7 @@ void audio_init(void)
 
     audio_thread_p = create_thread(audio_thread, audio_stack,
                   sizeof(audio_stack), CREATE_THREAD_FROZEN,
-                  audio_thread_name IF_PRIO(, PRIORITY_BACKGROUND)
+                  audio_thread_name IF_PRIO(, PRIORITY_SYSTEM)
                   IF_COP(, CPU));
 
 #ifdef PLAYBACK_VOICE

firmware/target/arm/sandisk/ata-c200_e200.c

@@ -140,7 +140,7 @@ long last_disk_activity = -1;
 static bool initialized = false;
 
 static long next_yield = 0;
-#define MIN_YIELD_PERIOD 2000
+#define MIN_YIELD_PERIOD 1000
 
 static tSDCardInfo card_info[2];
 static tSDCardInfo *currcard = NULL; /* current active card */