dwc3: core: clear DELAYP1TRANS with USB3PIPECTL register

Commit fd115e68971b ("dwc3: core: Don't perform controller and PHYs
soft reset") removed clearing DELAYP1TRANS. It is recommended to clear
DELAYP1TRANS bit with USB3PIPECTL register which controls USB
controller allowing USB QMP PHY low power transitions.

Change-Id: I54ba694f4c997bf5ecc540cee274e2cb07b77446
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 7aa0c7d..f4060d9 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -228,6 +228,7 @@
 static int dwc3_core_reset(struct dwc3 *dwc)
 {
 	int		ret;
+	u32	reg;
 
 	/* Reset PHYs */
 	usb_phy_reset(dwc->usb2_phy);
@@ -243,6 +244,10 @@
 		return ret;
 	}
 
+	reg = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0));
+	reg &= ~DWC3_GUSB3PIPECTL_DELAYP1TRANS;
+	dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), reg);
+
 	dwc3_notify_event(dwc, DWC3_CONTROLLER_RESET_EVENT);
 
 	dwc3_notify_event(dwc, DWC3_CONTROLLER_POST_RESET_EVENT);