V4L/DVB: gspca - main: Handle the audio device

When there is an audio device, use a lower alternate setting.
This patch does not fix correctly all audio and bandwidth problems.
Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/gspca.c

@@ -640,12 +640,16 @@ static struct usb_host_endpoint *get_ep(struct gspca_dev *gspca_dev)
 				   : USB_ENDPOINT_XFER_ISOC;
 	i = gspca_dev->alt;			/* previous alt setting */
 	if (gspca_dev->cam.reverse_alts) {
+		if (gspca_dev->audio)
+			i++;
 		while (++i < gspca_dev->nbalt) {
 			ep = alt_xfer(&intf->altsetting[i], xfer);
 			if (ep)
 				break;
 		}
 	} else {
+		if (gspca_dev->audio)
+			i--;
 		while (--i >= 0) {
 			ep = alt_xfer(&intf->altsetting[i], xfer);
 			if (ep)
@@ -2146,6 +2150,24 @@ int gspca_dev_probe2(struct usb_interface *intf,
 	gspca_dev->dev = dev;
 	gspca_dev->iface = intf->cur_altsetting->desc.bInterfaceNumber;
 	gspca_dev->nbalt = intf->num_altsetting;
+
+	/* check if any audio device */
+	if (dev->config->desc.bNumInterfaces != 1) {
+		int i;
+		struct usb_interface *intf2;
+
+		for (i = 0; i < dev->config->desc.bNumInterfaces; i++) {
+			intf2 = dev->config->interface[i];
+			if (intf2 != NULL
+			 && intf2->altsetting != NULL
+			 && intf2->altsetting->desc.bInterfaceClass ==
+					 USB_CLASS_AUDIO) {
+				gspca_dev->audio = 1;
+				break;
+			}
+		}
+	}
+
 	gspca_dev->sd_desc = sd_desc;
 	gspca_dev->nbufread = 2;
 	gspca_dev->empty_packet = -1;	/* don't check the empty packets */

drivers/media/video/gspca/gspca.h

@@ -198,6 +198,7 @@ struct gspca_dev {
 	struct mutex read_lock;		/* read protection */
 	struct mutex queue_lock;	/* ISOC queue protection */
 	int usb_err;			/* USB error - protected by usb_lock */
+	u16 pkt_size;			/* ISOC packet size */
 #ifdef CONFIG_PM
 	char frozen;			/* suspend - resume */
 #endif
@@ -208,7 +209,7 @@ struct gspca_dev {
 	__u8 iface;			/* USB interface number */
 	__u8 alt;			/* USB alternate setting */
 	__u8 nbalt;			/* number of USB alternate settings */
-	u16 pkt_size;			/* ISOC packet size */
+	u8 audio;			/* presence of audio device */
 };
 
 int gspca_dev_probe(struct usb_interface *intf,