[PATCH v2] powerpc/usb: fix bug of CPU hang when missing USB PHY clock
Shengzhou Liu
Shengzhou.Liu at freescale.com
Wed Aug 22 20:17:00 EST 2012
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 at freescale.com>
---
v2 changes: use spin_event_timeout() instead.
drivers/usb/host/ehci-fsl.c | 58 +++++++++++++++++++++++++++++-------------
drivers/usb/host/ehci-fsl.h | 1 +
include/linux/fsl_devices.h | 1 +
3 files changed, 42 insertions(+), 18 deletions(-)
diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index b7451b2..11ff4b4 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 8840368..dbd292e 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 */
diff --git a/include/linux/fsl_devices.h b/include/linux/fsl_devices.h
index 15be561..ccfc4bb 100644
--- a/include/linux/fsl_devices.h
+++ b/include/linux/fsl_devices.h
@@ -19,6 +19,7 @@
#define FSL_UTMI_PHY_DLY 10 /*As per P1010RM, delay for UTMI
PHY CLK to become stable - 10ms*/
+#define FSL_USB_PHY_CLK_TIMEOUT 1000 /* uSec */
#define FSL_USB_VER_OLD 0
#define FSL_USB_VER_1_6 1
#define FSL_USB_VER_2_2 2
--
1.6.4
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