[PATCH] usb: dwc2: Disable all EP's on disconnect

[Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx>]

Disabling all EP's allow to reset EP's to initial state.
On disconnect disable all EP's instead of just killing
all requests. Because of some platform didn't catch
disconnect event, same stuff added to
dwc2_hsotg_core_init_disconnected() function when USB
reset detected on the bus.
In dwc2_hsotg_ep_disable() function before locking
hsotg->lock, check if it locked by calling functions
then unlock. Lock again on exit if it was locked.
Same lock checking flow added to dwc2_hsotg_udc_stop()
function.

Signed-off-by: Minas Harutyunyan <hminas@xxxxxxxxxxxx>
---
 drivers/usb/dwc2/gadget.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 220c0f9b89b0..30975731812e 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -3109,6 +3109,8 @@ static void kill_all_requests(struct dwc2_hsotg *hsotg,
 		dwc2_hsotg_txfifo_flush(hsotg, ep->fifo_index);
 }
 
+static int dwc2_hsotg_ep_disable(struct usb_ep *ep);
+
 /**
  * dwc2_hsotg_disconnect - disconnect service
  * @hsotg: The device state.
@@ -3127,13 +3129,12 @@ void dwc2_hsotg_disconnect(struct dwc2_hsotg *hsotg)
 	hsotg->connected = 0;
 	hsotg->test_mode = 0;
 
+	/* all endpoints should be shutdown */
 	for (ep = 0; ep < hsotg->num_of_eps; ep++) {
 		if (hsotg->eps_in[ep])
-			kill_all_requests(hsotg, hsotg->eps_in[ep],
-					  -ESHUTDOWN);
+			dwc2_hsotg_ep_disable(&hsotg->eps_in[ep]->ep);
 		if (hsotg->eps_out[ep])
-			kill_all_requests(hsotg, hsotg->eps_out[ep],
-					  -ESHUTDOWN);
+			dwc2_hsotg_ep_disable(&hsotg->eps_out[ep]->ep);
 	}
 
 	call_gadget(hsotg, disconnect);
@@ -3191,13 +3192,23 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg,
 	u32 val;
 	u32 usbcfg;
 	u32 dcfg = 0;
+	int ep;
 
 	/* Kill any ep0 requests as controller will be reinitialized */
 	kill_all_requests(hsotg, hsotg->eps_out[0], -ECONNRESET);
 
-	if (!is_usb_reset)
+	if (!is_usb_reset) {
 		if (dwc2_core_reset(hsotg, true))
 			return;
+	} else {
+		/* all endpoints should be shutdown */
+		for (ep = 1; ep < hsotg->num_of_eps; ep++) {
+			if (hsotg->eps_in[ep])
+				dwc2_hsotg_ep_disable(&hsotg->eps_in[ep]->ep);
+			if (hsotg->eps_out[ep])
+				dwc2_hsotg_ep_disable(&hsotg->eps_out[ep]->ep);
+		}
+	}
 
 	/*
 	 * we must now enable ep0 ready for host detection and then
@@ -3993,6 +4004,7 @@ static int dwc2_hsotg_ep_disable(struct usb_ep *ep)
 	unsigned long flags;
 	u32 epctrl_reg;
 	u32 ctrl;
+	int locked;
 
 	dev_dbg(hsotg->dev, "%s(ep %p)\n", __func__, ep);
 
@@ -4008,6 +4020,8 @@ static int dwc2_hsotg_ep_disable(struct usb_ep *ep)
 
 	epctrl_reg = dir_in ? DIEPCTL(index) : DOEPCTL(index);
 
+	locked = spin_trylock(&hsotg->lock);
+	spin_unlock(&hsotg->lock);
 	spin_lock_irqsave(&hsotg->lock, flags);
 
 	ctrl = dwc2_readl(hsotg, epctrl_reg);
@@ -4033,6 +4047,9 @@ static int dwc2_hsotg_ep_disable(struct usb_ep *ep)
 	hs_ep->fifo_size = 0;
 
 	spin_unlock_irqrestore(&hsotg->lock, flags);
+	if (!locked)
+		spin_lock(&hsotg->lock);
+
 	return 0;
 }
 
@@ -4316,6 +4333,7 @@ static int dwc2_hsotg_udc_stop(struct usb_gadget *gadget)
 	struct dwc2_hsotg *hsotg = to_hsotg(gadget);
 	unsigned long flags = 0;
 	int ep;
+	int locked;
 
 	if (!hsotg)
 		return -ENODEV;
@@ -4328,6 +4346,8 @@ static int dwc2_hsotg_udc_stop(struct usb_gadget *gadget)
 			dwc2_hsotg_ep_disable(&hsotg->eps_out[ep]->ep);
 	}
 
+	locked = spin_trylock(&hsotg->lock);
+	spin_unlock(&hsotg->lock);
 	spin_lock_irqsave(&hsotg->lock, flags);
 
 	hsotg->driver = NULL;
@@ -4335,6 +4355,8 @@ static int dwc2_hsotg_udc_stop(struct usb_gadget *gadget)
 	hsotg->enabled = 0;
 
 	spin_unlock_irqrestore(&hsotg->lock, flags);
+	if (!locked)
+		spin_lock(&hsotg->lock);
 
 	if (!IS_ERR_OR_NULL(hsotg->uphy))
 		otg_set_peripheral(hsotg->uphy->otg, NULL);
-- 
2.11.0