On Tue, 1 Feb 2011, Maulik Mankad wrote:
> On Mon, Jan 31, 2011 at 8:27 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> >>
> >> Since RNDIS is disabled by default the Configuration descriptor also
> >> shows UMS as the first interface.
> >
> > That sounds like a bug. The gadget should know what its own interfaces
> > are! Is the UMS interface number 0 or number 2?
>
> UMS is assigned interface number 2 from usb_interface_id().
>
> > What value does the bNumInterfaces field have in the config descriptor?
>
> bNumInterfaces field shows 2 interfaces only which is correct(UMS and
> ADB) since RNDIS is disbaled.
> But RNDIS is also assigned interface id even though its disabled. This
> seems to be creating problems.
This appears to be a bug in composite.c. If a function fails to bind,
the interface numbers it has allocated are not released.
Does this patch help?
Alan Stern
Index: usb-2.6/drivers/usb/gadget/composite.c
===================================================================
--- usb-2.6.orig/drivers/usb/gadget/composite.c
+++ usb-2.6/drivers/usb/gadget/composite.c
@@ -106,13 +106,17 @@ int usb_add_function(struct usb_configur
/* REVISIT *require* function->bind? */
if (function->bind) {
+ unsigned old_id = config->next_interface_id;
+
value = function->bind(config, function);
if (value < 0) {
list_del(&function->list);
function->config = NULL;
+ config->next_interface_id = old_id;
+ goto done;
}
- } else
- value = 0;
+ }
+ value = 0;
/* We allow configurations that don't work at both speeds.
* If we run into a lowspeed Linux system, treat it the same
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
