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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <cd8c177e-7840-4636-a039-dbe8884b3d2b@lunn.ch>
Date:   Tue, 18 Jul 2023 00:27:02 +0200
From:   Andrew Lunn <andrew@...n.ch>
To:     Marco Felsch <m.felsch@...gutronix.de>
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

> +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