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

19 Oct 2012


      Hi,
On Thu, 18 Oct 2012 06:21:56 +0200
Marek Vasut marex@denx.de wrote:
...
Dear Shengzhou Liu,
...
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.
Signed-off-by: Shengzhou Liu Shengzhou.Liu@freescale.com
CCing PPC experts.
...
...
...
@@ -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);

you moved the USB interface enabling before the PHY CLK check but the
commit description doesn't mention why it is needed. It would be good
to mention the reason in the commit log.
Thanks,
Anatolij

    

Anatolij Gustschin