Re: [PATCH v8 03/13] phy: tegra: xusb: Move usb3 port init for Tegra210

Vinod Koul
2021-04-01T05:16:42Z

On 31-03-21, 18:32, Thierry Reding wrote:
> On Tue, Mar 30, 2021 at 07:42:53PM +0530, Vinod Koul wrote:
> > Hi Thierry,
> >
> > On 25-03-21, 17:40, Thierry Reding wrote:
> >
> > > +static struct tegra_xusb_usb3_port *
> > > +tegra210_lane_to_usb3_port(struct tegra_xusb_lane *lane)
> > > +{
> > > + int port;
> > > +
> > > + if (!lane || !lane->pad || !lane->pad->padctl)
> > > + return NULL;
> >
> > This looks problematic to me, so if lane is NULL, it will still go ahead
> > and check lane->pad which would result in NULL pointer dereference.
>
> No, this isn't going to result in a NULL pointer dereference because the
> compiler will short-circuit this if the first expression is true. If the
> lane parameter is NULL, then the entire expression is going to be true
> no matter what lane->pad and lane->pad->padctl evaluate to (because of
> the logical OR) and hence the compiler knows that it can skip the rest.

Yes, that is correct. I assumed wrongly, so:

Acked-By: Vinod Koul <vkoul@kernel.org>

--
~Vinod