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Subject: Re: [PATCH] net: stmmac: manage errors returned by
 of_get_mac_address()
To:     Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        peppe.cavallaro@st.com, alexandre.torgue@st.com,
        joabreu@synopsys.com, davem@davemloft.net, netdev@vger.kernel.org
Cc:     linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
References: <20190727192137.27881-1-martin.blumenstingl@googlemail.com>
From:   Neil Armstrong <narmstrong@baylibre.com>
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Organization: Baylibre
Message-ID: <afb321f0-5754-f916-7461-8cd062526a34@baylibre.com>
Date:   Mon, 29 Jul 2019 15:03:39 +0200
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In-Reply-To: <20190727192137.27881-1-martin.blumenstingl@googlemail.com>
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On 27/07/2019 21:21, Martin Blumenstingl wrote:
> Commit d01f449c008a ("of_net: add NVMEM support to of_get_mac_address")
> added support for reading the MAC address from an nvmem-cell. This
> required changing the logic to return an error pointer upon failure.
> 
> If stmmac is loaded before the nvmem provider driver then
> of_get_mac_address() return an error pointer with -EPROBE_DEFER.
> 
> Propagate this error so the stmmac driver will be probed again after the
> nvmem provider driver is loaded.
> Default to a random generated MAC address in case of any other error,
> instead of using the error pointer as MAC address.
> 
> Fixes: d01f449c008a ("of_net: add NVMEM support to of_get_mac_address")
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 73fc2524372e..154daf4d1072 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -370,6 +370,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
>  		return ERR_PTR(-ENOMEM);
>  
>  	*mac = of_get_mac_address(np);
> +	if (IS_ERR(*mac)) {
> +		if (PTR_ERR(*mac) == -EPROBE_DEFER)
> +			return ERR_CAST(*mac);
> +
> +		*mac = NULL;
> +	}
> +
>  	plat->interface = of_get_phy_mode(np);
>  
>  	/* Some wrapper drivers still rely on phy_node. Let's save it while
> 

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>