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

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Message-ID: <20230718083841.p67wflhjlwnu56j4@pengutronix.de>
Date:   Tue, 18 Jul 2023 10:38:41 +0200
From:   Marco Felsch <m.felsch@...gutronix.de>
To:     Andrew Lunn <andrew@...n.ch>
Cc:     davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org,
        pabeni@...hat.com, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
        peppe.cavallaro@...com, alexandre.torgue@...s.st.com,
        joabreu@...opsys.com, mcoquelin.stm32@...il.com,
        netdev@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        linux-stm32@...md-mailman.stormreply.com,
        linux-arm-kernel@...ts.infradead.org, kernel@...gutronix.de
Subject: Re: [PATCH net-next 2/2] net: stmmac: platform: add support for
 phy-supply

On 23-07-18, Andrew Lunn wrote:
> > +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.

You mean to move it under the enable path.

> > @@ -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.

Good point didn't consider WOL. Is there a way to check if WOL is
enabled?

Regards,
  Marco

> 
> > @@ -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
>