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>

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 60aeaca..fd2a440 100644 (file)
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -347,6 +347,7 @@ static int xhci_plat_suspend(struct device *dev)
 {
        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
@@ -356,7 +357,12 @@ static int xhci_plat_suspend(struct device *dev)
         * 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)
@@ -364,6 +370,9 @@ static int xhci_plat_resume(struct device *dev)
        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 */