fixed synchronisation issues by changing work_queue function and redu…

…ced latency through smaller buffers

Change-Id: I96fc227d9b38eb2e7a8f3ded68ef027f182624fc

drivers/usb/gadget/f_audio.c

@@ -43,7 +43,7 @@ static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
  */
 #define F_AUDIO_AC_INTERFACE	0
 #define F_AUDIO_AS_INTERFACE	1
-#define F_AUDIO_NUM_INTERFACES	2
+#define F_AUDIO_NUM_INTERFACES	1
 
 /* B.3.1  Standard AC Interface Descriptor */
 static struct usb_interface_descriptor ac_interface_desc __initdata = {
@@ -54,23 +54,23 @@ static struct usb_interface_descriptor ac_interface_desc __initdata = {
 	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
 };
 
-DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
+DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
 
 #define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
 /* 1 input terminal, 1 output terminal and 1 feature unit */
 #define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
 	+ UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
 /* B.3.2  Class-Specific AC Interface Descriptor */
-static struct uac1_ac_header_descriptor_2 ac_header_desc = {
+static struct uac1_ac_header_descriptor_1 ac_header_desc = {
 	.bLength =		UAC_DT_AC_HEADER_LENGTH,
 	.bDescriptorType =	USB_DT_CS_INTERFACE,
 	.bDescriptorSubtype =	UAC_HEADER,
 	.bcdADC =		__constant_cpu_to_le16(0x0100),
 	.wTotalLength =		__constant_cpu_to_le16(UAC_DT_TOTAL_LENGTH),
 	.bInCollection =	F_AUDIO_NUM_INTERFACES,
 	.baInterfaceNr = {
-		[0] =		F_AUDIO_AC_INTERFACE,
-		[1] =		F_AUDIO_AS_INTERFACE,
+		[0] =		1,
+		/*[1] =		F_AUDIO_AS_INTERFACE,*/
 	}
 };
 
@@ -193,7 +193,7 @@ static struct uac_iso_endpoint_descriptor as_iso_out_desc __initdata = {
 	.bDescriptorType =	USB_DT_CS_ENDPOINT,
 	.bDescriptorSubtype =	UAC_EP_GENERAL,
 	.bmAttributes = 	1,
-	.bLockDelayUnits =	1,
+	.bLockDelayUnits =	2,
 	.wLockDelay =		__constant_cpu_to_le16(1),
 };
 

drivers/usb/gadget/f_uac1.c

@@ -25,8 +25,9 @@ static int req_count = 256;
 module_param(req_count, int, S_IRUGO);
 MODULE_PARM_DESC(req_count, "ISO OUT endpoint request count");
 
-/*static int audio_buf_size = 48000; */
-static int audio_buf_size = 32000;
+static int audio_buf_size = 1440; 
+//static int audio_buf_size = 2000; 
+/*static int audio_buf_size = 24000; */
 module_param(audio_buf_size, int, S_IRUGO);
 MODULE_PARM_DESC(audio_buf_size, "Audio buffer size");
 
@@ -225,7 +226,7 @@ static struct uac_iso_endpoint_descriptor as_iso_out_desc __initdata = {
 	.bDescriptorType =	USB_DT_CS_ENDPOINT,
 	.bDescriptorSubtype =	UAC_EP_GENERAL,
 	.bmAttributes = 	0,
-	.bLockDelayUnits =	2,
+	.bLockDelayUnits =	1,
 	.wLockDelay =		__constant_cpu_to_le16(1),
 };
 
@@ -313,19 +314,21 @@ static void f_audio_playback_work(struct work_struct *data)
 	struct f_audio *audio = container_of(data, struct f_audio,
 					playback_work);
 	struct f_audio_buf *play_buf;
-
-	spin_lock_irq(&audio->lock);
-	if (list_empty(&audio->play_queue)) {
-		spin_unlock_irq(&audio->lock);
-		return;
-	}
-	play_buf = list_first_entry(&audio->play_queue,
-			struct f_audio_buf, list);
-	list_del(&play_buf->list);
-	spin_unlock_irq(&audio->lock);
-
-	u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
-	f_audio_buffer_free(play_buf);
+
+    while (1) {
+        spin_lock_irq(&audio->lock);
+        if (list_empty(&audio->play_queue)) {
+            spin_unlock_irq(&audio->lock);
+            return;
+        }
+        play_buf = list_first_entry(&audio->play_queue,
+                struct f_audio_buf, list);
+        list_del(&play_buf->list);
+        spin_unlock_irq(&audio->lock);
+
+        u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
+        f_audio_buffer_free(play_buf);
+    }
 }
 
 static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
@@ -337,19 +340,29 @@ static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
 
 	if (!copy_buf)
 		return -EINVAL;
-
+
+
 	/* Copy buffer is full, add it to the play_queue */
-	if (audio_buf_size - copy_buf->actual < req->actual) {
+    if (audio_buf_size - copy_buf->actual < req->actual) {
 		list_add_tail(&copy_buf->list, &audio->play_queue);
 		schedule_work(&audio->playback_work);
 		copy_buf = f_audio_buffer_alloc(audio_buf_size);
 		if (IS_ERR(copy_buf))
 			return -ENOMEM;
 	}
+
+
 
 	memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 	copy_buf->actual += req->actual;
 	audio->copy_buf = copy_buf;
+
+    /*
+    if (audio->copy_buf->actual > 2000) {
+        u_audio_playback(&audio->card, audio->copy_buf->buf, audio->copy_buf->actual);
+        audio->copy_buf->actual = 0;
+    }
+    */
 
 	err = usb_ep_queue(ep, req, GFP_ATOMIC);
 	if (err)
@@ -782,16 +795,21 @@ int __init control_selector_init(struct f_audio *audio)
 
 	mute_control.data[UAC__CUR] = 0x00;
 
-	volume_control.data[UAC__CUR] = 0x0000;
-	volume_control.data[UAC__MIN] = 0x8000;
-	volume_control.data[UAC__MAX] = 0x7FFF;
-	volume_control.data[UAC__RES] = 0x000A;
+	//volume_control.data[UAC__CUR] = 0x0000;
+	//volume_control.data[UAC__MIN] = 0x8000;
+	//volume_control.data[UAC__MAX] = 0x7FFF;
+	//volume_control.data[UAC__RES] = 0x000A;
 
 
+	//volume_control.data[UAC__CUR] = (signed short)-14336;
+	//volume_control.data[UAC__MIN] = (signed short)-16384;
+	//volume_control.data[UAC__MAX] = (signed short)16384;
+	//volume_control.data[UAC__RES] = (signed short)1024;
+
 	volume_control.data[UAC__CUR] = (signed short)-14336;
 	volume_control.data[UAC__MIN] = (signed short)-16384;
-	volume_control.data[UAC__MAX] = (signed short)16384;
-	volume_control.data[UAC__RES] = (signed short)1024;
+	volume_control.data[UAC__MAX] = (signed short)3041;
+	volume_control.data[UAC__RES] = (signed short)259;
 
 
 	return 0;

drivers/usb/gadget/u_uac1.c

@@ -179,6 +179,7 @@ static size_t u_audio_playback(struct gaudio *card, void *buf, size_t count)
 	ssize_t result;
 	snd_pcm_sframes_t frames;
     unsigned char regvol = 0xff;
+    int retries = 0;
 
 try_again:
 	if (runtime->status->state == SNDRV_PCM_STATE_XRUN ||
@@ -193,6 +194,7 @@ static size_t u_audio_playback(struct gaudio *card, void *buf, size_t count)
 	}
 
     /* try volume change*/
+
     if (snd->mute != mute_control.data[UAC__CUR]) {
         INFO(snd->card, "mute: 0x%x\n", mute_control.data[UAC__CUR]);
         snd->mute = mute_control.data[UAC__CUR];
@@ -207,14 +209,20 @@ static size_t u_audio_playback(struct gaudio *card, void *buf, size_t count)
         snd_pcm_kernel_ioctl(substream, 0x400141f9, &regvol);
         snd->volume = volume_control.data[UAC__CUR];
     } 
-
+
+
 	frames = bytes_to_frames(runtime, count);
 	old_fs = get_fs();
 	set_fs(KERNEL_DS);
 	result = snd_pcm_lib_write(snd->substream, buf, frames);
 	if (result != frames) {
 		ERROR(card, "Playback error: %d\n", (int)result);
 		set_fs(old_fs);
+        retries += 1;
+        if (retries > 10){
+            ERROR(card, "Too many playback retries: %d\n", retries);
+            return 0;
+        }
 		goto try_again;
 	}
 	set_fs(old_fs);