1 files changed, 40 insertions, 8 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 9eb085f359ce..98114c2827c0 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -544,6 +544,7 @@ static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned int length)
 int dwc3_event_buffers_setup(struct dwc3 *dwc)
 {
 	struct dwc3_event_buffer	*evt;
+	u32				reg;
 
 	if (!dwc->ev_buf)
 		return 0;
@@ -556,8 +557,10 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc)
 			upper_32_bits(evt->dma));
 	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0),
 			DWC3_GEVNTSIZ_SIZE(evt->length));
-	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), 0);
 
+	/* Clear any stale event */
+	reg = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0));
+	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), reg);
 	return 0;
 }
 
@@ -584,7 +587,10 @@ void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
 	dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(0), 0);
 	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), DWC3_GEVNTSIZ_INTMASK
 			| DWC3_GEVNTSIZ_SIZE(0));
-	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), 0);
+
+	/* Clear any stale event */
+	reg = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0));
+	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), reg);
 }
 
 static void dwc3_core_num_eps(struct dwc3 *dwc)
@@ -2336,6 +2342,19 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 	u32 reg;
 	int i;
 
+	if (!pm_runtime_suspended(dwc->dev) && !PMSG_IS_AUTO(msg)) {
+		dwc->susphy_state = (dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)) &
+				    DWC3_GUSB2PHYCFG_SUSPHY) ||
+				    (dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0)) &
+				    DWC3_GUSB3PIPECTL_SUSPHY);
+		/*
+		 * TI AM62 platform requires SUSPHY to be
+		 * enabled for system suspend to work.
+		 */
+		if (!dwc->susphy_state)
+			dwc3_enable_susphy(dwc, true);
+	}
+
 	switch (dwc->current_dr_role) {
 	case DWC3_GCTL_PRTCAP_DEVICE:
 		if (pm_runtime_suspended(dwc->dev))
@@ -2454,6 +2473,11 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
 		break;
 	}
 
+	if (!PMSG_IS_AUTO(msg)) {
+		/* restore SUSPHY state to that before system suspend. */
+		dwc3_enable_susphy(dwc, dwc->susphy_state);
+	}
+
 	return 0;
 }
 
@@ -2499,7 +2523,11 @@ static int dwc3_runtime_resume(struct device *dev)
 
 	switch (dwc->current_dr_role) {
 	case DWC3_GCTL_PRTCAP_DEVICE:
-		dwc3_gadget_process_pending_events(dwc);
+		if (dwc->pending_events) {
+			pm_runtime_put(dwc->dev);
+			dwc->pending_events = false;
+			enable_irq(dwc->irq_gadget);
+		}
 		break;
 	case DWC3_GCTL_PRTCAP_HOST:
 	default:
@@ -2552,7 +2580,7 @@ static int dwc3_suspend(struct device *dev)
 static int dwc3_resume(struct device *dev)
 {
 	struct dwc3	*dwc = dev_get_drvdata(dev);
-	int		ret;
+	int		ret = 0;
 
 	pinctrl_pm_select_default_state(dev);
 
@@ -2560,14 +2588,12 @@ static int dwc3_resume(struct device *dev)
 	pm_runtime_set_active(dev);
 
 	ret = dwc3_resume_common(dwc, PMSG_RESUME);
-	if (ret) {
+	if (ret)
 		pm_runtime_set_suspended(dev);
-		return ret;
-	}
 
 	pm_runtime_enable(dev);
 
-	return 0;
+	return ret;
 }
 
 static void dwc3_complete(struct device *dev)
@@ -2589,6 +2615,12 @@ static void dwc3_complete(struct device *dev)
 static const struct dev_pm_ops dwc3_dev_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
 	.complete = dwc3_complete,
+
+	/*
+	 * Runtime suspend halts the controller on disconnection. It relies on
+	 * platforms with custom connection notification to start the controller
+	 * again.
+	 */
 	SET_RUNTIME_PM_OPS(dwc3_runtime_suspend, dwc3_runtime_resume,
 			dwc3_runtime_idle)
 };