[RFC 5/6] usb: usb_parse_endpoint must not count duplicated endpoints

[Oliver Neukum <oneukum@suse.com>]

When an interface is parsed the number of endpoints claimed to exist
is compared to the number of endpoint descriptors actually found.
Duplicated endpoints are not parsed in usb_parse_endpoint but
usb_parse_interface counts them. That makes no sense.
To correct this usb_parse_endpoint needs to return feedback
about the validity of parsed endpoints.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/core/config.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 055910fc6b19..50acc9021247 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -254,7 +254,7 @@ static bool config_endpoint_is_duplicate(struct usb_host_config *config,
 static int usb_parse_endpoint(struct device *ddev, int cfgno,
 		struct usb_host_config *config, int inum, int asnum,
 		struct usb_host_interface *ifp, int num_ep,
-		unsigned char *buffer, int size)
+		unsigned char *buffer, int size, bool *valid)
 {
 	struct usb_device *udev = to_usb_device(ddev);
 	unsigned char *buffer0 = buffer;
@@ -270,6 +270,7 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno,
 
 	buffer += d->bLength;
 	size -= d->bLength;
+	*valid = false;
 
 	if (d->bDescriptorType != USB_DT_ENDPOINT)
 		goto skip_to_next_endpoint_or_interface_descriptor;
@@ -313,6 +314,7 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno,
 		}
 	}
 
+	*valid = true;
 	endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
 	++ifp->desc.bNumEndpoints;
 
@@ -581,14 +583,17 @@ static int usb_parse_interface(struct device *ddev, int cfgno,
 	/* Parse all the endpoint descriptors */
 	n = 0;
 	while (size >= sizeof(struct usb_descriptor_header)) { /* minimum length to get bDescriptorType */
+		bool valid;
+
 		if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 		     == USB_DT_INTERFACE)
 			break;
 		retval = usb_parse_endpoint(ddev, cfgno, config, inum, asnum,
-				alt, num_ep, buffer, size);
+				alt, num_ep, buffer, size, &valid);
 		if (retval < 0)
 			return retval;
-		++n;
+		if (valid)
+			++n;
 
 		buffer += retval;
 		size -= retval;
-- 
2.44.0