From 61d5b51b6425b09da807e2ce31232e8c56f172c9 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Wed, 19 Apr 2017 16:55:46 +0300
Subject: [PATCH 201/286] usb: host: xhci-plat: enable clk in resume timing

This patch enables the clk in resume timing when device_may_wakeup()
is false. Otherwise, kernel panic happens when R-Car resumes the system
from Suspend-to-RAM because the clk is disabled.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 835e4241e714fbd659838618466766b132823da3)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
 drivers/usb/host/xhci-plat.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -328,6 +328,7 @@ static int xhci_plat_suspend(struct devi
 {
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
+	int ret;
 
 	/*
 	 * xhci_suspend() needs `do_wakeup` to know whether host is allowed
@@ -337,7 +338,12 @@ static int xhci_plat_suspend(struct devi
 	 * reconsider this when xhci_plat_suspend enlarges its scope, e.g.,
 	 * also applies to runtime suspend.
 	 */
-	return xhci_suspend(xhci, device_may_wakeup(dev));
+	ret = xhci_suspend(xhci, device_may_wakeup(dev));
+
+	if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk))
+		clk_disable_unprepare(xhci->clk);
+
+	return ret;
 }
 
 static int xhci_plat_resume(struct device *dev)
@@ -345,6 +351,9 @@ static int xhci_plat_resume(struct devic
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 
+	if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk))
+		clk_prepare_enable(xhci->clk);
+
 	return xhci_resume(xhci, 0);
 }
 #endif /* CONFIG_PM_SLEEP */