usb: dwc2: gadget: Prevent wrong extcon notification

In sometimes, USB disconnection triggers enumeration-done interrupt
even though it is false state. Actually, this interrupt is ignored by
dwc2 irq handler, but extcon notfication can be mis-delivered to
user-space. Thus, this patch make worker determined the current state
by itself, and it also prevent some cases which have chance for wrong
notification such as repeatedly connect/disconnecting usb cable.

Change-Id: Iff88cf2c030b627f3d2da23930b10e9f3a84c8e1
Signed-off-by: Dongwoo Lee <dwoo08.lee@samsung.com>

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index cbe1b560b649cfa45334d940557383b8bc2125b3..faa9ce0fb9461b7e8c44b99fd30024d7da7b22d3 100644 (file)
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -876,7 +876,6 @@ struct dwc2_hsotg {
 #if IS_ENABLED(CONFIG_EXTCON)
        struct extcon_dev *edev;
        struct work_struct extcon_work;
-       unsigned int extcon_state;
 #endif /* CONFIG_EXTCON */
 #endif /* CONFIG_USB_DWC2_PERIPHERAL || CONFIG_USB_DWC2_DUAL_ROLE */
 };

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index c232f2dcee07775695d5cf41790282b21c95f0e3..bb26bccdc78686c8076a896150838975b84fb9a5 100644 (file)
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -41,18 +41,26 @@ static const unsigned int supported_cable[] = {
        EXTCON_NONE,
 };
 
-static void dwc2_gadget_extcon_notify(struct dwc2_hsotg *hsotg, bool on)
+static inline void dwc2_gadget_extcon_notify(struct dwc2_hsotg *hsotg)
 {
-       hsotg->extcon_state = on;
        queue_work(system_power_efficient_wq, &hsotg->extcon_work);
 }
 
+static inline void dwc2_gadget_cancel_extcon_work(struct dwc2_hsotg *hsotg)
+{
+       cancel_work_sync(&hsotg->extcon_work);
+}
+
 static void dwc2_gadget_extcon_work(struct work_struct *work)
 {
        struct dwc2_hsotg *hsotg = container_of(work, struct dwc2_hsotg,
                                                extcon_work);
+       u32 usb_status = dwc2_readl(hsotg->regs + GOTGCTL);
 
-       extcon_set_cable_state_(hsotg->edev, EXTCON_USB, hsotg->extcon_state);
+       if (usb_status & (GOTGCTL_ASESVLD | GOTGCTL_BSESVLD))
+               extcon_set_cable_state_(hsotg->edev, EXTCON_USB, true);
+       else
+               extcon_set_cable_state_(hsotg->edev, EXTCON_USB, false);
 }
 
 static int dwc2_gadget_extcon_init(struct dwc2_hsotg *hsotg)
@@ -79,7 +87,11 @@ static int dwc2_gadget_extcon_init(struct dwc2_hsotg *hsotg)
        return 0;
 }
 #else
-static inline void dwc2_gadget_extcon_notify(struct dwc2_hsotg *hsotg, bool on)
+static inline void dwc2_gadget_extcon_notify(struct dwc2_hsotg *hsotg)
+{
+}
+
+static inline void dwc2_gadget_cancel_extcon_work(struct dwc2_hsotg *hsotg)
 {
 }
 
@@ -2573,7 +2585,7 @@ irq_retry:
                        u32 flags = GOTGCTL_ASESVLD | GOTGCTL_BSESVLD;
 
                        if (!(usb_status & flags))
-                               dwc2_gadget_extcon_notify(hsotg, false);
+                               dwc2_gadget_extcon_notify(hsotg);
                }
        }
 
@@ -2583,7 +2595,7 @@ irq_retry:
                dwc2_hsotg_irq_enumdone(hsotg);
 
                if (hsotg->g_extcon_notify)
-                       dwc2_gadget_extcon_notify(hsotg, true);
+                       dwc2_gadget_extcon_notify(hsotg);
        }
 
        if (gintsts & (GINTSTS_OEPINT | GINTSTS_IEPINT)) {
@@ -3329,11 +3341,22 @@ static int dwc2_hsotg_pullup(struct usb_gadget *gadget, int is_on)
                dwc2_hsotg_core_init_disconnected(hsotg, false);
                dwc2_hsotg_core_connect(hsotg);
        } else {
+               /*
+                * If gadget disconnection makes also PHY pullup
+                * disconnection, usb controller cannot generate
+                * interrupt for usb connection and thus extcon
+                * notification won't be working. In order to prevent
+                * this situation, we have to keep PHY pullup alive
+                * when extcon notification is activated.
+                */
+               if (hsotg->g_extcon_notify)
+                       goto skip_change;
                dwc2_hsotg_core_disconnect(hsotg);
                dwc2_hsotg_disconnect(hsotg);
                hsotg->enabled = 0;
        }
 
+skip_change:
        hsotg->gadget.speed = USB_SPEED_UNKNOWN;
        spin_unlock_irqrestore(&hsotg->lock, flags);
 
@@ -3757,6 +3780,9 @@ int dwc2_gadget_init(struct dwc2_hsotg *hsotg, int irq)
  */
 int dwc2_hsotg_remove(struct dwc2_hsotg *hsotg)
 {
+       if (hsotg->g_extcon_notify)
+               dwc2_gadget_cancel_extcon_work(hsotg);
+
        usb_del_gadget_udc(&hsotg->gadget);
        dwc2_hsotg_ep_free_request(&hsotg->eps_out[0]->ep, hsotg->ctrl_req);
 
@@ -3780,6 +3806,9 @@ int dwc2_hsotg_suspend(struct dwc2_hsotg *hsotg)
                }
        }
 
+       if (hsotg->g_extcon_notify)
+               dwc2_gadget_cancel_extcon_work(hsotg);
+
        if (hsotg->driver) {
                int ep;