[PATCH v3 04/28] usb: gadget: f_tcm: Fix Get/SetInterface return value

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

Check to make sure that the GetInterface and SetInterface are for valid
interface. Return proper alternate setting number on GetInterface.

Fixes: 0b8b1a1fede0 ("usb: gadget: f_tcm: Provide support to get alternate setting in tcm function")
Cc: stable@vger.kernel.org
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
---
 drivers/usb/gadget/function/f_tcm.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index 5ce97723376e..f996878e1aea 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -2046,9 +2046,14 @@ static void tcm_delayed_set_alt(struct work_struct *wq)
 
 static int tcm_get_alt(struct usb_function *f, unsigned intf)
 {
-	if (intf == bot_intf_desc.bInterfaceNumber)
+	struct f_uas *fu = to_f_uas(f);
+
+	if (fu->iface != intf)
+		return -EOPNOTSUPP;
+
+	if (fu->flags & USBG_IS_BOT)
 		return USB_G_ALT_INT_BBB;
-	if (intf == uasp_intf_desc.bInterfaceNumber)
+	else if (fu->flags & USBG_IS_UAS)
 		return USB_G_ALT_INT_UAS;
 
 	return -EOPNOTSUPP;
@@ -2058,6 +2063,9 @@ static int tcm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 {
 	struct f_uas *fu = to_f_uas(f);
 
+	if (fu->iface != intf)
+		return -EOPNOTSUPP;
+
 	if ((alt == USB_G_ALT_INT_BBB) || (alt == USB_G_ALT_INT_UAS)) {
 		struct guas_setup_wq *work;
 
-- 
2.28.0