1 files changed, 72 insertions, 31 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 68e6a7b6fd81..458e7c6cc002 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -100,7 +100,10 @@ static int dwc3_get_dr_mode(struct dwc3 *dwc)
 	return 0;
 }
 
-void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
+static void dwc3_event_buffers_cleanup(struct dwc3 *dwc);
+static int dwc3_event_buffers_setup(struct dwc3 *dwc);
+
+static void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
 {
 	u32 reg;
 
@@ -108,8 +111,69 @@ void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
 	reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
 	reg |= DWC3_GCTL_PRTCAPDIR(mode);
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
+}
+
+static void __dwc3_set_mode(struct work_struct *work)
+{
+	struct dwc3 *dwc = work_to_dwc(work);
+	unsigned long flags;
+	int ret;
+
+	if (!dwc->desired_dr_role)
+		return;
+
+	if (dwc->desired_dr_role == dwc->current_dr_role)
+		return;
+
+	if (dwc->dr_mode != USB_DR_MODE_OTG)
+		return;
+
+	switch (dwc->current_dr_role) {
+	case DWC3_GCTL_PRTCAP_HOST:
+		dwc3_host_exit(dwc);
+		break;
+	case DWC3_GCTL_PRTCAP_DEVICE:
+		dwc3_gadget_exit(dwc);
+		dwc3_event_buffers_cleanup(dwc);
+		break;
+	default:
+		break;
+	}
+
+	spin_lock_irqsave(&dwc->lock, flags);
+
+	dwc3_set_prtcap(dwc, dwc->desired_dr_role);
 
-	dwc->current_dr_role = mode;
+	dwc->current_dr_role = dwc->desired_dr_role;
+
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	switch (dwc->desired_dr_role) {
+	case DWC3_GCTL_PRTCAP_HOST:
+		ret = dwc3_host_init(dwc);
+		if (ret)
+			dev_err(dwc->dev, "failed to initialize host\n");
+		break;
+	case DWC3_GCTL_PRTCAP_DEVICE:
+		dwc3_event_buffers_setup(dwc);
+		ret = dwc3_gadget_init(dwc);
+		if (ret)
+			dev_err(dwc->dev, "failed to initialize peripheral\n");
+		break;
+	default:
+		break;
+	}
+}
+
+void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->desired_dr_role = mode;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	queue_work(system_power_efficient_wq, &dwc->drd_work);
 }
 
 u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type)
@@ -721,21 +785,6 @@ static int dwc3_core_init(struct dwc3 *dwc)
 		goto err4;
 	}
 
-	switch (dwc->dr_mode) {
-	case USB_DR_MODE_PERIPHERAL:
-		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
-		break;
-	case USB_DR_MODE_HOST:
-		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_HOST);
-		break;
-	case USB_DR_MODE_OTG:
-		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_OTG);
-		break;
-	default:
-		dev_warn(dwc->dev, "Unsupported mode %d\n", dwc->dr_mode);
-		break;
-	}
-
 	/*
 	 * ENDXFER polling is available on version 3.10a and later of
 	 * the DWC_usb3 controller. It is NOT available in the
@@ -853,6 +902,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 
 	switch (dwc->dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
+		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 		ret = dwc3_gadget_init(dwc);
 		if (ret) {
 			if (ret != -EPROBE_DEFER)
@@ -861,6 +911,7 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 		}
 		break;
 	case USB_DR_MODE_HOST:
+		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
 		ret = dwc3_host_init(dwc);
 		if (ret) {
 			if (ret != -EPROBE_DEFER)
@@ -869,19 +920,8 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 		}
 		break;
 	case USB_DR_MODE_OTG:
-		ret = dwc3_host_init(dwc);
-		if (ret) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(dev, "failed to initialize host\n");
-			return ret;
-		}
-
-		ret = dwc3_gadget_init(dwc);
-		if (ret) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(dev, "failed to initialize gadget\n");
-			return ret;
-		}
+		INIT_WORK(&dwc->drd_work, __dwc3_set_mode);
+		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 		break;
 	default:
 		dev_err(dev, "Unsupported mode of operation %d\n", dwc->dr_mode);
@@ -901,8 +941,9 @@ static void dwc3_core_exit_mode(struct dwc3 *dwc)
 		dwc3_host_exit(dwc);
 		break;
 	case USB_DR_MODE_OTG:
-		dwc3_host_exit(dwc);
+		dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 		dwc3_gadget_exit(dwc);
+		flush_work(&dwc->drd_work);
 		break;
 	default:
 		/* do nothing */