Re: [net-next PATCH v5 15/15] net: dpaa2-mac: Add ACPI support for DPAA2 MAC driver

From: Calvin Johnson <calvin.johnson@oss.nxp.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>,
	Grant Likely <grant.likely@arm.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Jeremy Linton <jeremy.linton@arm.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Cristi Sovaiala <cristian.sovaiala@nxp.com>,
	Florin Laurentiu Chiculita <florinlaurentiu.chiculita@nxp.com>,
	Ioana Ciornei <ioana.ciornei@nxp.com>,
	Madalin Bucur <madalin.bucur@oss.nxp.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	Marcin Wojtas <mw@semihalf.com>,
	Pieter Jansen Van Vuuren <pieter.jansenvv@bamboosystems.io>,
	Jon <jon@solid-run.com>, Saravana Kannan <saravanak@google.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Laurentiu Tudor <laurentiu.tudor@nxp.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"linux.cj" <linux.cj@gmail.com>,
	Diana Madalina Craciun <diana.craciun@nxp.com>,
	netdev <netdev@vger.kernel.org>,
	linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
	ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Ioana Radulescu <ruxandra.radulescu@nxp.com>,
	Jakub Kicinski <kuba@kernel.org>
Subject: Re: [net-next PATCH v5 15/15] net: dpaa2-mac: Add ACPI support for DPAA2 MAC driver
Date: Tue, 16 Feb 2021 15:29:59 +0530	[thread overview]
Message-ID: <20210216095959.GA1015@lsv03152.swis.in-blr01.nxp.com> (raw)
In-Reply-To: <CAHp75Vfcpk_4OQDpk_rvySJbXAyzAubt-n=ckFzggdo9fKvJ4A@mail.gmail.com>

On Mon, Feb 15, 2021 at 05:15:36PM +0200, Andy Shevchenko wrote:
> On Mon, Feb 15, 2021 at 5:13 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> >
> > On Mon, Feb 15, 2021 at 2:33 PM Calvin Johnson
> > <calvin.johnson@oss.nxp.com> wrote:
> > > On Mon, Feb 08, 2021 at 04:28:31PM +0000, Russell King - ARM Linux admin wrote:
> >
> > ...
> >
> > > I think of_phy_is_fixed_link() needs to be fixed. I'll add below fix.
> > >
> > > --- a/drivers/net/mdio/of_mdio.c
> > > +++ b/drivers/net/mdio/of_mdio.c
> > > @@ -439,6 +439,9 @@ bool of_phy_is_fixed_link(struct device_node *np)
> > >         int len, err;
> > >         const char *managed;
> > >
> > > +       if (!np)
> > > +               return false;
> >
> > AFAICS this doesn't add anything: all of the of_* APIs should handle
> > OF nodes being NULL below.
> >
> > >         /* New binding */
> > >         dn = of_get_child_by_name(np, "fixed-link");
> > >         if (dn) {
> 
> Yes, of_get_next_child() and of_get_property() are NULL aware.
> 
> So, the check is redundant.
Yes, all the function calls in of_phy_is_fixed_link() handles NULL properly.
I don't see any way this function can oops.

Regards
Calvin