[U-Boot] [PATCH v3] powerpc/usb: fix bug of CPU hang when missing USB PHY clock

Shengzhou Liu
2012-10-22T05:18:24Z

when missing USB PHY clock, u-boot will hang during USB
initialization when issuing "usb start". We should check
USBGP[PHY_CLK_VALID] bit to avoid CPU hanging in this case.

Due to controller issue of PHY_CLK_VALID in ULPI mode, we set
USB_EN before checking PHY_CLK_VALID, otherwise PHY_CLK_VALID
doesn't work.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
---
against master branch of upstream u-boot tree
v3: added explanation for set USB_EN earlier for ULPI case.
v2: integrated Marek's comment to use single negation.

drivers/usb/host/ehci-fsl.c | 22 ++++++++++++++++------
1 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 7b8f033..f54b408 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -30,6 +30,18 @@

#include "ehci.h"

+/* Check USB PHY clock valid */
+static int usb_phy_clk_valid(struct usb_ehci *ehci)
+{
+ if (!((in_be32(&ehci->control) & PHY_CLK_VALID) ||
+ in_be32(&ehci->prictrl))) {
+ printf("USB PHY clock invalid!\n");
+ return 0;
+ } else {
+ return 1;
+ }
+}
+
/*
* Create the appropriate control structures to manage
* a new EHCI host controller.
@@ -82,18 +94,16 @@ int ehci_hcd_init(int index, struct ehci_hccr **hccr, struct ehci_hcor **hcor)
udelay(1000); /* delay required for PHY Clk to appear */
#endif
out_le32(&(*hcor)->or_portsc[0], PORT_PTS_UTMI);
+ setbits_be32(&ehci->control, USB_EN);
} else {
-#if defined(CONFIG_SYS_FSL_USB_INTERNAL_UTMI_PHY)
- clrbits_be32(&ehci->control, UTMI_PHY_EN);
setbits_be32(&ehci->control, PHY_CLK_SEL_ULPI);
+ clrsetbits_be32(&ehci->control, UTMI_PHY_EN, USB_EN);
udelay(1000); /* delay required for PHY Clk to appear */
-#endif
+ if (!usb_phy_clk_valid(ehci))
+ return -EINVAL;
out_le32(&(*hcor)->or_portsc[0], PORT_PTS_ULPI);
}

- /* Enable interface. */
- setbits_be32(&ehci->control, USB_EN);
-
out_be32(&ehci->prictrl, 0x0000000c);
out_be32(&ehci->age_cnt_limit, 0x00000040);
out_be32(&ehci->sictrl, 0x00000001);
--
1.6.4