powerpc/usb: fix bug of CPU hang when missing USB PHY clock

when missing USB PHY clock, kernel booting up will hang during USB
initialization. We should check USBGP[PHY_CLK_VALID] bit to avoid
CPU hanging in this case.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 41 insertions, 18 deletions

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index b7451b29c5a..11ff4b4dc7a 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -210,11 +210,11 @@ static void usb_hcd_fsl_remove(struct usb_hcd *hcd,
         usb_put_hcd(hcd);
 }
 
-static void ehci_fsl_setup_phy(struct usb_hcd *hcd,
+static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
                                enum fsl_usb2_phy_modes phy_mode,
                                unsigned int port_offset)
 {
-        u32 portsc, temp;
+        u32 portsc;
         struct ehci_hcd *ehci = hcd_to_ehci(hcd);
         void __iomem *non_ehci = hcd->regs;
         struct device *dev = hcd->self.controller;
@@ -232,9 +232,15 @@ static void ehci_fsl_setup_phy(struct usb_hcd *hcd,
         case FSL_USB2_PHY_ULPI:
                 if (pdata->controller_ver) {
                         /* controller version 1.6 or above */
-                        temp = in_be32(non_ehci + FSL_SOC_USB_CTRL);
-                        out_be32(non_ehci + FSL_SOC_USB_CTRL, temp |
-                                USB_CTRL_USB_EN | ULPI_PHY_CLK_SEL);
+                        setbits32(non_ehci + FSL_SOC_USB_CTRL,
+                                        ULPI_PHY_CLK_SEL);
+                        /*
+                         * Due to controller issue of PHY_CLK_VALID in ULPI
+                         * mode, we set USB_CTRL_USB_EN before checking
+                         * PHY_CLK_VALID, otherwise PHY_CLK_VALID doesn't work.
+                         */
+                        clrsetbits_be32(non_ehci + FSL_SOC_USB_CTRL,
+                                        UTMI_PHY_EN, USB_CTRL_USB_EN);
                 }
                 portsc |= PORT_PTS_ULPI;
                 break;
@@ -247,9 +253,7 @@ static void ehci_fsl_setup_phy(struct usb_hcd *hcd,
         case FSL_USB2_PHY_UTMI:
                 if (pdata->controller_ver) {
                         /* controller version 1.6 or above */
-                        temp = in_be32(non_ehci + FSL_SOC_USB_CTRL);
-                        out_be32(non_ehci + FSL_SOC_USB_CTRL, temp |
-                                UTMI_PHY_EN | USB_CTRL_USB_EN);
+                        setbits32(non_ehci + FSL_SOC_USB_CTRL, UTMI_PHY_EN);
                         mdelay(FSL_UTMI_PHY_DLY);  /* Delay for UTMI PHY CLK to
                                                 become stable - 10ms*/
                 }
@@ -262,23 +266,34 @@ static void ehci_fsl_setup_phy(struct usb_hcd *hcd,
         case FSL_USB2_PHY_NONE:
                 break;
         }
+
+        if ((pdata->controller_ver) && ((phy_mode == FSL_USB2_PHY_ULPI) ||
+                        (phy_mode == FSL_USB2_PHY_UTMI))) {
+                /* check PHY_CLK_VALID to get phy clk valid */
+                if (!spin_event_timeout(in_be32(non_ehci + FSL_SOC_USB_CTRL) &
+                                PHY_CLK_VALID, FSL_USB_PHY_CLK_TIMEOUT, 0)) {
+                        printk(KERN_WARNING "fsl-ehci: USB PHY clock invalid\n");
+                        return -EINVAL;
+                }
+        }
+
         ehci_writel(ehci, portsc, &ehci->regs->port_status[port_offset]);
+
+        if (phy_mode != FSL_USB2_PHY_ULPI)
+                setbits32(non_ehci + FSL_SOC_USB_CTRL, USB_CTRL_USB_EN);
+
+        return 0;
 }
 
-static void ehci_fsl_usb_setup(struct ehci_hcd *ehci)
+static int ehci_fsl_usb_setup(struct ehci_hcd *ehci)
 {
         struct usb_hcd *hcd = ehci_to_hcd(ehci);
         struct fsl_usb2_platform_data *pdata;
         void __iomem *non_ehci = hcd->regs;
-        u32 temp;
 
         pdata = hcd->self.controller->platform_data;
 
-        /* Enable PHY interface in the control reg. */
         if (pdata->have_sysif_regs) {
-                temp = in_be32(non_ehci + FSL_SOC_USB_CTRL);
-                out_be32(non_ehci + FSL_SOC_USB_CTRL, temp | 0x00000004);
-
                 /*
                 * Turn on cache snooping hardware, since some PowerPC platforms
                 * wholly rely on hardware to deal with cache coherent
@@ -293,7 +308,8 @@ static void ehci_fsl_usb_setup(struct ehci_hcd *ehci)
 
         if ((pdata->operating_mode == FSL_USB2_DR_HOST) ||
                         (pdata->operating_mode == FSL_USB2_DR_OTG))
-                ehci_fsl_setup_phy(hcd, pdata->phy_mode, 0);
+                if (ehci_fsl_setup_phy(hcd, pdata->phy_mode, 0))
+                        return -EINVAL;
 
         if (pdata->operating_mode == FSL_USB2_MPH_HOST) {
                 unsigned int chip, rev, svr;
@@ -307,9 +323,12 @@ static void ehci_fsl_usb_setup(struct ehci_hcd *ehci)
                         ehci->has_fsl_port_bug = 1;
 
                 if (pdata->port_enables & FSL_USB2_PORT0_ENABLED)
-                        ehci_fsl_setup_phy(hcd, pdata->phy_mode, 0);
+                        if (ehci_fsl_setup_phy(hcd, pdata->phy_mode, 0))
+                                return -EINVAL;
+
                 if (pdata->port_enables & FSL_USB2_PORT1_ENABLED)
-                        ehci_fsl_setup_phy(hcd, pdata->phy_mode, 1);
+                        if (ehci_fsl_setup_phy(hcd, pdata->phy_mode, 1))
+                                return -EINVAL;
         }
 
         if (pdata->have_sysif_regs) {
@@ -322,12 +341,15 @@ static void ehci_fsl_usb_setup(struct ehci_hcd *ehci)
 #endif
                 out_be32(non_ehci + FSL_SOC_USB_SICTRL, 0x00000001);
         }
+
+        return 0;
 }
 
 /* called after powerup, by probe or system-pm "wakeup" */
 static int ehci_fsl_reinit(struct ehci_hcd *ehci)
 {
-        ehci_fsl_usb_setup(ehci);
+        if (ehci_fsl_usb_setup(ehci))
+                return -EINVAL;
         ehci_port_power(ehci, 0);
 
         return 0;
diff --git a/drivers/usb/host/ehci-fsl.h b/drivers/usb/host/ehci-fsl.h
index 88403684d10..dbd292e9f0a 100644
--- a/drivers/usb/host/ehci-fsl.h
+++ b/drivers/usb/host/ehci-fsl.h
@@ -61,4 +61,5 @@
 #define PLL_RESET               (1<<8)
 #define UTMI_PHY_EN             (1<<9)
 #define ULPI_PHY_CLK_SEL        (1<<10)
+#define PHY_CLK_VALID           (1<<17)
 #endif                          /* _EHCI_FSL_H */