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

[Marek Vasut]

Dear Liu Shengzhou-B36685,

> > -----Original Message-----
> > 
> > > +/* 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))) {
> > 
> > (!A && !B) condition can certainly be done without the double negation
> > ;-)
> 
> [Shengzhou] Yes, using !(A||B) is also okay:)

Good, you did your logic homework well. Now go one step further:

if (a || b)
 return 1;

printf()
return 0;

How will that work?

> 
> > > +		printf("USB PHY clock invalid!\n");
> > 
> > debug() ?
> 
> [Shengzhou] No, it's not for debug purpose, it should be printf() as a
> necessary info.

OK.

Best regards,
Marek Vasut