Index: sys/dev/usb/controller/dwc3.h
===================================================================
--- sys/dev/usb/controller/dwc3.h
+++ sys/dev/usb/controller/dwc3.h
@@ -59,6 +59,8 @@
 #define	DWC3_GBUSERRADDRHI	0xc134
 #define	DWC3_GPRTBIMAPLO	0xc138
 #define	DWC3_GHWPARAMS0		0xc140
+#define	DWC3_GHWPARAMS0_MODE_DUALROLEDEVICE	0x2
+#define	DWC3_GHWPARAMS0_MODE_MASK		0x3
 #define	DWC3_GHWPARAMS1		0xc144
 #define	DWC3_GHWPARAMS2		0xc148
 #define	DWC3_GHWPARAMS3		0xc14C
@@ -93,6 +95,7 @@
 #define	 DWC3_GUSB3PIPECTL0_PHYSOFTRST		(1 << 31)
 #define	 DWC3_GUSB3PIPECTL0_DISRXDETINP3	(1 << 28)
 #define	 DWC3_GUSB3PIPECTL0_DELAYP1TRANS	(1 << 18)
+#define	 DWC3_GUSB3PIPECTL0_SUSPENDUSB3		(1 << 17)
 
 #define	DWC3_GTXFIFOSIZ(x)	(0xc300 + 0x4 * (x))
 #define	DWC3_GRXFIFOSIZ(x)	(0xc380 + 0x4 * (x))
Index: sys/dev/usb/controller/dwc3.c
===================================================================
--- sys/dev/usb/controller/dwc3.c
+++ sys/dev/usb/controller/dwc3.c
@@ -79,6 +79,8 @@
 	phandle_t		node;
 	phy_t			usb2_phy;
 	phy_t			usb3_phy;
+	uint32_t		snpsid;
+	uint32_t		hwparams[9];
 };
 
 #define	DWC3_WRITE(_sc, _off, _val)		\
@@ -181,10 +183,16 @@
 
 	phy2 = DWC3_READ(sc, DWC3_GUSB2PHYCFG0);
 	phy2 |= DWC3_GUSB2PHYCFG0_PHYSOFTRST;
+	if ((sc->hwparams[0] & DWC3_GHWPARAMS0_MODE_MASK) ==
+	    DWC3_GHWPARAMS0_MODE_DUALROLEDEVICE)
+		phy2 &= ~DWC3_GUSB2PHYCFG0_SUSPENDUSB20;
 	DWC3_WRITE(sc, DWC3_GUSB2PHYCFG0, phy2);
 
 	phy3 = DWC3_READ(sc, DWC3_GUSB3PIPECTL0);
 	phy3 |= DWC3_GUSB3PIPECTL0_PHYSOFTRST;
+	if ((sc->hwparams[0] & DWC3_GHWPARAMS0_MODE_MASK) ==
+	    DWC3_GHWPARAMS0_MODE_DUALROLEDEVICE)
+		phy3 &= ~DWC3_GUSB3PIPECTL0_SUSPENDUSB3;
 	DWC3_WRITE(sc, DWC3_GUSB3PIPECTL0, phy3);
 
 	DELAY(1000);
@@ -249,6 +257,7 @@
 static void
 snps_dwc3_do_quirks(struct snps_dwc3_softc *sc)
 {
+	struct xhci_softc *xsc;
 	uint32_t reg;
 
 	reg = DWC3_READ(sc, DWC3_GUSB2PHYCFG0);
@@ -258,7 +267,8 @@
 		reg |= DWC3_GUSB2PHYCFG0_U2_FREECLK_EXISTS;
 	if (device_has_property(sc->dev, "snps,dis_u2_susphy_quirk"))
 		reg &= ~DWC3_GUSB2PHYCFG0_SUSPENDUSB20;
-	else
+	else if ((sc->hwparams[0] & DWC3_GHWPARAMS0_MODE_MASK) ==
+	    DWC3_GHWPARAMS0_MODE_DUALROLEDEVICE)
 		reg |= DWC3_GUSB2PHYCFG0_SUSPENDUSB20;
 	if (device_has_property(sc->dev, "snps,dis_enblslpm_quirk"))
 		reg &= ~DWC3_GUSB2PHYCFG0_ENBLSLPM;
@@ -276,7 +286,41 @@
 		reg &= ~DWC3_GUSB3PIPECTL0_DELAYP1TRANS;
 	if (device_has_property(sc->dev, "snps,dis_rxdet_inp3_quirk"))
 		reg |= DWC3_GUSB3PIPECTL0_DISRXDETINP3;
+	if (device_has_property(sc->dev, "snps,dis_u3_susphy_quirk"))
+		reg &= ~DWC3_GUSB3PIPECTL0_SUSPENDUSB3;
+	else if ((sc->hwparams[0] & DWC3_GHWPARAMS0_MODE_MASK) ==
+	    DWC3_GHWPARAMS0_MODE_DUALROLEDEVICE)
+		reg |= DWC3_GUSB3PIPECTL0_SUSPENDUSB3;
 	DWC3_WRITE(sc, DWC3_GUSB3PIPECTL0, reg);
+
+	/* Port Disable does not work on <= 3.00a. Disable PORT_PED. */
+	if ((sc->snpsid & 0xffff) <= 0x300a) {
+		xsc = &sc->sc;
+		xsc->sc_quirks |= XHCI_QUIRK_DISABLE_PORT_PED;
+	}
+}
+
+static void
+snps_swc3_get_ctrlparams(struct snps_dwc3_softc *sc)
+{
+	const bus_size_t offs[] = {
+	    DWC3_GHWPARAMS0, DWC3_GHWPARAMS1, DWC3_GHWPARAMS2, DWC3_GHWPARAMS3,
+	    DWC3_GHWPARAMS4, DWC3_GHWPARAMS5, DWC3_GHWPARAMS6, DWC3_GHWPARAMS7,
+	    DWC3_GHWPARAMS8,
+	};
+	int i;
+
+	sc->snpsid = DWC3_READ(sc, DWC3_GSNPSID);
+	if (bootverbose)
+		device_printf(sc->dev, "snps id: %#012x\n", sc->snpsid);
+	for (i = 0; i < nitems(sc->hwparams) && i < nitems(offs); i++) {
+		sc->hwparams[i] = DWC3_READ(sc, offs[i]);
+#ifdef DWC3_DEBUG
+		if (bootverbose)
+			device_printf(sc->dev, "hwparams[%d]: %#012x\n",
+			    i, sc->hwparams[i]);
+#endif
+	}
 }
 
 static int
@@ -326,8 +370,7 @@
 	sc->bst = rman_get_bustag(sc->mem_res);
 	sc->bsh = rman_get_bushandle(sc->mem_res);
 
-	if (bootverbose)
-		device_printf(dev, "snps id: %x\n", DWC3_READ(sc, DWC3_GSNPSID));
+	snps_swc3_get_ctrlparams(sc);
 
 	/* Get the phys */
 	sc->node = ofw_bus_get_node(dev);