Re: [PATCH net-next 2/2] net: stmmac: platform: add support for phy-supply

From: Andrew Lunn <andrew@lunn.ch>
To: Marco Felsch <m.felsch@pengutronix.de>
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
	pabeni@redhat.com, robh+dt@kernel.org,
	krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
	peppe.cavallaro@st.com, alexandre.torgue@foss.st.com,
	joabreu@synopsys.com, mcoquelin.stm32@gmail.com,
	netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org, kernel@pengutronix.de
Subject: Re: [PATCH net-next 2/2] net: stmmac: platform: add support for phy-supply
Date: Tue, 18 Jul 2023 00:27:02 +0200	[thread overview]
Message-ID: <cd8c177e-7840-4636-a039-dbe8884b3d2b@lunn.ch> (raw)
In-Reply-To: <20230717164307.2868264-2-m.felsch@pengutronix.de>

> +static int stmmac_phy_power(struct platform_device *pdev,
> +			    struct plat_stmmacenet_data *plat,
> +			    bool enable)
> +{
> +	struct regulator *regulator = plat->phy_regulator;
> +	int ret = 0;
> +
> +	if (regulator) {
> +		if (enable)
> +			ret = regulator_enable(regulator);
> +		else
> +			regulator_disable(regulator);
> +	}
> +
> +	if (ret)
> +		dev_err(&pdev->dev, "Fail to enable regulator\n");

'enable' is only correct 50% of the time.

> @@ -742,6 +786,8 @@ static int __maybe_unused stmmac_pltfr_suspend(struct device *dev)
>  	if (priv->plat->exit)
>  		priv->plat->exit(pdev, priv->plat->bsp_priv);
>  
> +	stmmac_phy_power_off(pdev, priv->plat);
> +

What about WOL? You probably want to leave the PHY with power in that
case.

> @@ -757,6 +803,11 @@ static int __maybe_unused stmmac_pltfr_resume(struct device *dev)
>  	struct net_device *ndev = dev_get_drvdata(dev);
>  	struct stmmac_priv *priv = netdev_priv(ndev);
>  	struct platform_device *pdev = to_platform_device(dev);
> +	int ret;
> +
> +	ret = stmmac_phy_power_on(pdev, priv->plat);
> +	if (ret)
> +		return ret;

And this needs to balance with _suspend when WOL is being used.

    Andrew