usb: gadget: f_uac2: fix superspeed transfer

On page 362 of the USB3.2 specification (
https://usb.org/sites/default/files/usb_32_20210125.zip),
The 'SuperSpeed Endpoint Companion Descriptor' shall only be returned
by Enhanced SuperSpeed devices that are operating at Gen X speed.
Each endpoint described in an interface is followed by a 'SuperSpeed
Endpoint Companion Descriptor'.

If users use SuperSpeed UDC, host can't recognize the device if endpoint
doesn't have 'SuperSpeed Endpoint Companion Descriptor' followed.

Currently in the uac2 driver code:
1. ss_epout_desc_comp follows ss_epout_desc;
2. ss_epin_fback_desc_comp follows ss_epin_fback_desc;
3. ss_epin_desc_comp follows ss_epin_desc;
4. Only ss_ep_int_desc endpoint doesn't have 'SuperSpeed Endpoint
Companion Descriptor' followed, so we should add it.

Fixes: eaf6cbe0 ("usb: gadget: f_uac2: add volume and mute support")
Cc: stable <stable@kernel.org>
Signed-off-by: Jing Leng <jleng@ambarella.com>
Signed-off-by: Jack Pham <quic_jackp@quicinc.com>
Link: https://lore.kernel.org/r/20220721014815.14453-1-quic_jackp@quicinc.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/function/f_uac2.c

@@ -291,6 +291,12 @@ static struct usb_endpoint_descriptor ss_ep_int_desc = {
 	.bInterval = 4,
 };
 
+static struct usb_ss_ep_comp_descriptor ss_ep_int_desc_comp = {
+	.bLength = sizeof(ss_ep_int_desc_comp),
+	.bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
+	.wBytesPerInterval = cpu_to_le16(6),
+};
+
 /* Audio Streaming OUT Interface - Alt0 */
 static struct usb_interface_descriptor std_as_out_if0_desc = {
 	.bLength = sizeof std_as_out_if0_desc,
@@ -604,7 +610,8 @@ static struct usb_descriptor_header *ss_audio_desc[] = {
 	(struct usb_descriptor_header *)&in_feature_unit_desc,
 	(struct usb_descriptor_header *)&io_out_ot_desc,
 
-  (struct usb_descriptor_header *)&ss_ep_int_desc,
+	(struct usb_descriptor_header *)&ss_ep_int_desc,
+	(struct usb_descriptor_header *)&ss_ep_int_desc_comp,
 
 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
@@ -800,6 +807,7 @@ static void setup_headers(struct f_uac2_opts *opts,
 	struct usb_ss_ep_comp_descriptor *epout_desc_comp = NULL;
 	struct usb_ss_ep_comp_descriptor *epin_desc_comp = NULL;
 	struct usb_ss_ep_comp_descriptor *epin_fback_desc_comp = NULL;
+	struct usb_ss_ep_comp_descriptor *ep_int_desc_comp = NULL;
 	struct usb_endpoint_descriptor *epout_desc;
 	struct usb_endpoint_descriptor *epin_desc;
 	struct usb_endpoint_descriptor *epin_fback_desc;
@@ -827,6 +835,7 @@ static void setup_headers(struct f_uac2_opts *opts,
 		epin_fback_desc = &ss_epin_fback_desc;
 		epin_fback_desc_comp = &ss_epin_fback_desc_comp;
 		ep_int_desc = &ss_ep_int_desc;
+		ep_int_desc_comp = &ss_ep_int_desc_comp;
 	}
 
 	i = 0;
@@ -855,8 +864,11 @@ static void setup_headers(struct f_uac2_opts *opts,
 	if (EPOUT_EN(opts))
 		headers[i++] = USBDHDR(&io_out_ot_desc);
 
-	if (FUOUT_EN(opts) || FUIN_EN(opts))
+	if (FUOUT_EN(opts) || FUIN_EN(opts)) {
 		headers[i++] = USBDHDR(ep_int_desc);
+		if (ep_int_desc_comp)
+			headers[i++] = USBDHDR(ep_int_desc_comp);
+	}
 
 	if (EPOUT_EN(opts)) {
 		headers[i++] = USBDHDR(&std_as_out_if0_desc);