[media] em28xx: simplify usb audio class handling

As far as we know devices can either have audio class or vendor class
usb interfaces but not both at the same time. Even if both interface
types could be provided by devices at the same time, the current code is
totally broken for that case.

So clean up and simplify the usb audio class handling by replacing
fields "has_audio_class" (device has usb audio class compliant
interface) and "has_alsa_audio" (device has vendor audio interface) in
struct em28xx with a single enum em28xx_usb_audio_type.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/usb/em28xx/em28xx-audio.c

@@ -893,7 +893,7 @@ static int em28xx_audio_init(struct em28xx *dev)
 	static int          devnr;
 	int		    err;
 
-	if (!dev->has_alsa_audio) {
+	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
 		/* This device does not support the extension (in this case
 		   the device is expecting the snd-usb-audio module or
 		   doesn't have analog audio support at all) */
@@ -975,7 +975,7 @@ static int em28xx_audio_fini(struct em28xx *dev)
 	if (dev == NULL)
 		return 0;
 
-	if (!dev->has_alsa_audio) {
+	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR) {
 		/* This device does not support the extension (in this case
 		   the device is expecting the snd-usb-audio module or
 		   doesn't have analog audio support at all) */
@@ -1003,7 +1003,7 @@ static int em28xx_audio_suspend(struct em28xx *dev)
 	if (dev == NULL)
 		return 0;
 
-	if (!dev->has_alsa_audio)
+	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
 		return 0;
 
 	em28xx_info("Suspending audio extension");
@@ -1017,7 +1017,7 @@ static int em28xx_audio_resume(struct em28xx *dev)
 	if (dev == NULL)
 		return 0;
 
-	if (!dev->has_alsa_audio)
+	if (dev->usb_audio_type != EM28XX_USB_AUDIO_VENDOR)
 		return 0;
 
 	em28xx_info("Resuming audio extension");

drivers/media/usb/em28xx/em28xx-cards.c

@@ -2931,9 +2931,9 @@ static void request_module_async(struct work_struct *work)
 #if defined(CONFIG_MODULES) && defined(MODULE)
 	if (dev->has_video)
 		request_module("em28xx-v4l");
-	if (dev->has_audio_class)
+	if (dev->usb_audio_type == EM28XX_USB_AUDIO_CLASS)
 		request_module("snd-usb-audio");
-	else if (dev->has_alsa_audio)
+	else if (dev->usb_audio_type == EM28XX_USB_AUDIO_VENDOR)
 		request_module("em28xx-alsa");
 	if (dev->board.has_dvb)
 		request_module("em28xx-dvb");
@@ -3180,7 +3180,7 @@ static int em28xx_usb_probe(struct usb_interface *interface,
 	struct usb_device *udev;
 	struct em28xx *dev = NULL;
 	int retval;
-	bool has_audio = false, has_video = false, has_dvb = false;
+	bool has_vendor_audio = false, has_video = false, has_dvb = false;
 	int i, nr, try_bulk;
 	const int ifnum = interface->altsetting[0].desc.bInterfaceNumber;
 	char *speed;
@@ -3262,7 +3262,7 @@ static int em28xx_usb_probe(struct usb_interface *interface,
 					break;
 				case 0x83:
 					if (usb_endpoint_xfer_isoc(e)) {
-						has_audio = true;
+						has_vendor_audio = true;
 					} else {
 						printk(KERN_INFO DRIVER_NAME
 						": error: skipping audio endpoint 0x83, because it uses bulk transfers !\n");
@@ -3318,7 +3318,7 @@ static int em28xx_usb_probe(struct usb_interface *interface,
 		}
 	}
 
-	if (!(has_audio || has_video || has_dvb)) {
+	if (!(has_vendor_audio || has_video || has_dvb)) {
 		retval = -ENODEV;
 		goto err_free;
 	}
@@ -3365,25 +3365,27 @@ static int em28xx_usb_probe(struct usb_interface *interface,
 	dev->devno = nr;
 	dev->model = id->driver_info;
 	dev->alt   = -1;
-	dev->is_audio_only = has_audio && !(has_video || has_dvb);
-	dev->has_alsa_audio = has_audio;
+	dev->is_audio_only = has_vendor_audio && !(has_video || has_dvb);
 	dev->has_video = has_video;
 	dev->ifnum = ifnum;
 
-	/* Checks if audio is provided by some interface */
+	if (has_vendor_audio) {
+		printk(KERN_INFO DRIVER_NAME ": Audio interface %i found %s\n",
+		       ifnum, "(Vendor Class)");
+		dev->usb_audio_type = EM28XX_USB_AUDIO_VENDOR;
+	}
+	/* Checks if audio is provided by a USB Audio Class interface */
 	for (i = 0; i < udev->config->desc.bNumInterfaces; i++) {
 		struct usb_interface *uif = udev->config->interface[i];
 		if (uif->altsetting[0].desc.bInterfaceClass == USB_CLASS_AUDIO) {
-			dev->has_audio_class = 1;
+			if (has_vendor_audio)
+				em28xx_err("em28xx: device seems to have vendor AND usb audio class interfaces !\n"
+					   "\t\tThe vendor interface will be ignored. Please contact the developers <linux-media@vger.kernel.org>\n");
+			dev->usb_audio_type = EM28XX_USB_AUDIO_CLASS;
 			break;
 		}
 	}
 
-	if (has_audio)
-		printk(KERN_INFO DRIVER_NAME
-		       ": Audio interface %i found %s\n",
-		       ifnum,
-		       dev->has_audio_class ? "(USB Audio Class)" : "(Vendor Class)");
 	if (has_video)
 		printk(KERN_INFO DRIVER_NAME
 		       ": Video interface %i found:%s%s\n",

drivers/media/usb/em28xx/em28xx-core.c

@@ -513,8 +513,7 @@ int em28xx_audio_setup(struct em28xx *dev)
 	    dev->chip_id == CHIP_ID_EM28178) {
 		/* Digital only device - don't load any alsa module */
 		dev->audio_mode.has_audio = false;
-		dev->has_audio_class = false;
-		dev->has_alsa_audio = false;
+		dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
 		return 0;
 	}
 
@@ -528,8 +527,8 @@ int em28xx_audio_setup(struct em28xx *dev)
 		cfg = EM28XX_CHIPCFG_AC97; /* Be conservative */
 	} else if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) == 0x00) {
 		/* The device doesn't have vendor audio at all */
-		dev->has_alsa_audio = false;
 		dev->audio_mode.has_audio = false;
+		dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
 		return 0;
 	} else if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) != EM28XX_CHIPCFG_AC97) {
 		if (dev->chip_id < CHIP_ID_EM2860 &&
@@ -560,7 +559,8 @@ int em28xx_audio_setup(struct em28xx *dev)
 		 */
 		em28xx_warn("AC97 chip type couldn't be determined\n");
 		dev->audio_mode.ac97 = EM28XX_NO_AC97;
-		dev->has_alsa_audio = false;
+		if (dev->usb_audio_type == EM28XX_USB_AUDIO_VENDOR)
+			dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
 		dev->audio_mode.has_audio = false;
 		goto init_audio;
 	}

drivers/media/usb/em28xx/em28xx.h

@@ -312,6 +312,12 @@ struct em28xx_audio_mode {
 	unsigned int has_audio:1;
 };
 
+enum em28xx_usb_audio_type {
+	EM28XX_USB_AUDIO_NONE = 0,
+	EM28XX_USB_AUDIO_CLASS,
+	EM28XX_USB_AUDIO_VENDOR,
+};
+
 /* em28xx has two audio inputs: tuner and line in.
    However, on most devices, an auxiliary AC97 codec device is used.
    The AC97 device may have several different inputs and outputs,
@@ -601,9 +607,8 @@ struct em28xx {
 	unsigned int is_em25xx:1;	/* em25xx/em276x/7x/8x family bridge */
 	unsigned char disconnected:1;	/* device has been diconnected */
 	unsigned int has_video:1;
-	unsigned int has_audio_class:1;
-	unsigned int has_alsa_audio:1;
 	unsigned int is_audio_only:1;
+	enum em28xx_usb_audio_type usb_audio_type;
 
 	struct em28xx_board board;