Date:   Tue, 31 Jan 2023 18:25:32 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     Marc Kleine-Budde <mkl@pengutronix.de>
Cc:     Arnd Bergmann <arnd@kernel.org>, Wei Fang <wei.fang@nxp.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Shenwei Wang <shenwei.wang@nxp.com>,
        Clark Wang <xiaoning.wang@nxp.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, ore@pengutronix.de,
        kernel@pengutronix.de
Subject: Re: [PATCH] [v2] fec: convert to gpio descriptor
Message-ID: <Y9lPDGUestsjdWVX@lunn.ch>
References: <20230126210648.1668178-1-arnd@kernel.org>
 <20230131153851.ua57vy7vc2xdasup@pengutronix.de>
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On Tue, Jan 31, 2023 at 04:38:51PM +0100, Marc Kleine-Budde wrote:
> On 26.01.2023 22:05:59, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> > 
> > The driver can be trivially converted, as it only triggers the gpio
> > pin briefly to do a reset, and it already only supports DT.
> > 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> On current net-next/main 6a8ab436831d ("Merge branch
> 'add-support-for-the-the-vsc7512-internal-copper-phys'") this causes the
> riot board (arch/arm/boot/dts/imx6dl-riotboard.dts) to not probe the
> fec:
> 
> | Jan 31 16:32:12 riot kernel: fec 2188000.ethernet: error -ENOENT: failed to get phy-reset-gpios
> | Jan 31 16:32:12 riot kernel: fec: probe of 2188000.ethernet failed with error -2

Hi Marc

Could you try swapping the devm_gpiod_get() for
devm_gpiod_get_optional().

It is kind of hidden, but:

-       else if (!gpio_is_valid(phy_reset))
-               return 0;

made the GPIO optional, since -2 is not a valid GPIO number and so it
would silently return.

The real fix will need to be a bit more complex, since we don't want
to do the sleeps etc if the GPIO is not present.

	Andrew