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

13 Feb 2012


      ...
-----Original Message-----
From: Andy Fleming [mailto:afleming@gmail.com]
Sent: Monday, February 13, 2012 4:14 PM
To: Liu Shengzhou-B36685; U-Boot list
Subject: Re: powerpc/usb: fix bug of CPU halt when missing USB PHY
clock
You moved the USB_EN setting:

/* Enable interface. */
setbits_be32(&ehci->control, USB_EN);


[...]

/* Enable interface. */
setbits_be32(&ehci->control, USB_EN);


Should we clear this bit if we don't find a valid clock? The patch
description didn't say why you moved this write.
Andy
To read ehci->control[PHY_CLK_VALID], we have to first enable it, or it will hang when reading control[PHY_CLK_VALID].
-Shengzhou