usb: gadget: f_uac2: fix bFirstInterface in composite gadget

[ Upstream commit 8813a59ed892305b5ac1b5b901740b1ad4b5fefa ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index 969cfe7413808c5b1bcc421b56d60fb6db65e57d..5474b5187be0a59fd675c0dcb644d791aaddb38b 100644 (file)
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -1040,6 +1040,8 @@ 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;
        agdev->ac_intf = ret;
        agdev->ac_alt = 0;