powerpc/usb: fix bug of kernel hang when initializing usb

BugLink: http://bugs.launchpad.net/bugs/971808

commit 28c56ea1431421dec51b7b229369e991481453df upstream.

If USB UTMI PHY is not enable, writing to portsc register will lead to
kernel hang during boot up.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 5 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index bc7f166395a..fc93d57609a 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -216,6 +216,8 @@ static void ehci_fsl_setup_phy(struct ehci_hcd *ehci,
                                unsigned int port_offset)
 {
         u32 portsc;
+        struct usb_hcd *hcd = ehci_to_hcd(ehci);
+        void __iomem *non_ehci = hcd->regs;
 
         portsc = ehci_readl(ehci, &ehci->regs->port_status[port_offset]);
         portsc &= ~(PORT_PTS_MSK | PORT_PTS_PTW);
@@ -231,6 +233,8 @@ static void ehci_fsl_setup_phy(struct ehci_hcd *ehci,
                 portsc |= PORT_PTS_PTW;
                 /* fall through */
         case FSL_USB2_PHY_UTMI:
+                /* enable UTMI PHY */
+                setbits32(non_ehci + FSL_SOC_USB_CTRL, CTRL_UTMI_PHY_EN);
                 portsc |= PORT_PTS_UTMI;
                 break;
         case FSL_USB2_PHY_NONE:
diff --git a/drivers/usb/host/ehci-fsl.h b/drivers/usb/host/ehci-fsl.h
index 49180622116..bea5013ab7f 100644
--- a/drivers/usb/host/ehci-fsl.h
+++ b/drivers/usb/host/ehci-fsl.h
@@ -45,5 +45,6 @@
 #define FSL_SOC_USB_PRICTRL     0x40c   /* NOTE: big-endian */
 #define FSL_SOC_USB_SICTRL      0x410   /* NOTE: big-endian */
 #define FSL_SOC_USB_CTRL        0x500   /* NOTE: big-endian */
+#define CTRL_UTMI_PHY_EN        (1<<9)
 #define SNOOP_SIZE_2GB          0x1e
 #endif                          /* _EHCI_FSL_H */