usb: gadget: s3c-hsotg: fix disconnect handling

This patch moves s3c_hsotg_disconnect function call from USBSusp interrupt
handler to SET_ADDRESS request handler.

It's because disconnected state can't be detected directly, because this
hardware doesn't support Disconnected interrupt for device mode. For both
Suspend and Disconnect events there is one interrupt USBSusp, but calling
s3c_hsotg_disconnect from this interrupt handler causes config reset in
composite layer, which is not undesirable for Suspended state.

For this reason s3c_hsotg_disconnect is called from SET_ADDRESS request
handler, which occurs always after disconnection, so we do disconnect
immediately before we are connected again. It's probably only way we
can do handle disconnection correctly.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/s3c-hsotg.c

@@ -1180,6 +1180,7 @@ static int s3c_hsotg_process_req_feature(struct s3c_hsotg *hsotg,
 }
 
 static void s3c_hsotg_enqueue_setup(struct s3c_hsotg *hsotg);
+static void s3c_hsotg_disconnect(struct s3c_hsotg *hsotg);
 
 /**
  * s3c_hsotg_process_control - process a control request
@@ -1221,6 +1222,7 @@ static void s3c_hsotg_process_control(struct s3c_hsotg *hsotg,
 	if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
 		switch (ctrl->bRequest) {
 		case USB_REQ_SET_ADDRESS:
+			s3c_hsotg_disconnect(hsotg);
 			dcfg = readl(hsotg->regs + DCFG);
 			dcfg &= ~DCFG_DevAddr_MASK;
 			dcfg |= ctrl->wValue << DCFG_DevAddr_SHIFT;
@@ -2537,7 +2539,6 @@ static irqreturn_t s3c_hsotg_irq(int irq, void *pw)
 		writel(GINTSTS_USBSusp, hsotg->regs + GINTSTS);
 
 		call_gadget(hsotg, suspend);
-		s3c_hsotg_disconnect(hsotg);
 	}
 
 	if (gintsts & GINTSTS_WkUpInt) {