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From: Shengzhou Liu <Shengzhou.Liu@freescale.com>
To: <linux-usb@vger.kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org,
	Shengzhou Liu <Shengzhou.Liu@freescale.com>
Subject: [PATCH] powerpc/usb: fix issue of CPU halt when missing USB PHY clock
Date: Wed, 1 Feb 2012 17:20:17 +0800	[thread overview]
Message-ID: <1328088017-9262-1-git-send-email-Shengzhou.Liu@freescale.com> (raw)

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

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
---
 drivers/usb/host/ehci-fsl.c |   11 +++++++++--
 drivers/usb/host/ehci-fsl.h |    1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index b556a72..834237e 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -239,7 +239,7 @@ static void ehci_fsl_setup_phy(struct ehci_hcd *ehci,
 	ehci_writel(ehci, portsc, &ehci->regs->port_status[port_offset]);
 }
 
-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;
@@ -299,12 +299,19 @@ static void ehci_fsl_usb_setup(struct ehci_hcd *ehci)
 #endif
 		out_be32(non_ehci + FSL_SOC_USB_SICTRL, 0x00000001);
 	}
+
+	if (!(in_be32(non_ehci + FSL_SOC_USB_CTRL) & CTRL_PHY_CLK_VALID)) {
+		printk(KERN_WARNING "fsl-ehci: USB PHY clock invalid\n");
+		return -1;
+	}
+	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 -1;
 	ehci_port_power(ehci, 0);
 
 	return 0;
diff --git a/drivers/usb/host/ehci-fsl.h b/drivers/usb/host/ehci-fsl.h
index 4918062..dd3dc47 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_PHY_CLK_VALID      (1 << 17)
 #define SNOOP_SIZE_2GB		0x1e
 #endif				/* _EHCI_FSL_H */
-- 
1.6.4

             reply	other threads:[~2012-02-01  9:21 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-01  9:20 Shengzhou Liu [this message]
2012-02-01 10:11 ` [PATCH] powerpc/usb: fix issue of CPU halt when missing USB PHY clock Pavan Kondeti
2012-02-02  3:31   ` Liu Shengzhou-B36685
2012-02-15  2:31     ` Benjamin Herrenschmidt
2012-02-16 10:16       ` Liu Shengzhou-B36685

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