usb: gadget: f_uac2: fix bFirstInterface in composite gadget

If there are multiple functions associated with a configuration, then
the UAC2 interfaces may not start at zero.  Set the correct first
interface number in the association descriptor so that the audio
interfaces are enumerated correctly in this case.

Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index 11fe788b430879d3559b5a6fda7a4a563cd22c34..d2dc1f00180b7869201afc1dbd82dcd4b126ab16 100644 (file)
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -524,6 +524,8 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
                dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
                return ret;
        }
+       iad_desc.bFirstInterface = ret;
+
        std_ac_if_desc.bInterfaceNumber = ret;
        uac2->ac_intf = ret;
        uac2->ac_alt = 0;