usb: dwc3: ep0: don't change to configured state too early

before changing to configured state, we need
to wait until gadget driver has had a chance
to process the request.

In case of USB_GADGET_DELAYED_STATUS, that means
we need to defer usb_gadget_set_state() until
the upcoming usb_ep_queue().

Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 007651c21638..7fa93f4bc507 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -148,6 +148,7 @@ static int __dwc3_gadget_ep0_queue(struct dwc3_ep *dep,
 
                 direction = !dwc->ep0_expect_in;
                 dwc->delayed_status = false;
+                usb_gadget_set_state(&dwc->gadget, USB_STATE_CONFIGURED);
 
                 if (dwc->ep0state == EP0_STATUS_PHASE)
                         __dwc3_ep0_do_control_status(dwc, dwc->eps[direction]);
@@ -533,8 +534,16 @@ static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
                 ret = dwc3_ep0_delegate_req(dwc, ctrl);
                 /* if the cfg matches and the cfg is non zero */
                 if (cfg && (!ret || (ret == USB_GADGET_DELAYED_STATUS))) {
-                        usb_gadget_set_state(&dwc->gadget,
-                                        USB_STATE_CONFIGURED);
+
+                        /*
+                         * only change state if set_config has already
+                         * been processed. If gadget driver returns
+                         * USB_GADGET_DELAYED_STATUS, we will wait
+                         * to change the state on the next usb_ep_queue()
+                         */
+                        if (ret == 0)
+                                usb_gadget_set_state(&dwc->gadget,
+                                                USB_STATE_CONFIGURED);
 
                         /*
                          * Enable transition to U1/U2 state when