netdev - Re: [PATCH 1/1] net: phy: dp83867: Disable IRQs on suspend

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Date:   Tue, 28 Feb 2023 16:05:27 +0100
From:   Andrew Lunn <andrew@...n.ch>
To:     Alexander Stein <alexander.stein@...tq-group.com>
Cc:     Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        "David S . Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>, netdev@...r.kernel.org
Subject: Re: [PATCH 1/1] net: phy: dp83867: Disable IRQs on suspend

> +static int dp83867_suspend(struct phy_device *phydev)
> +{
> +	/* Disable PHY Interrupts */
> +	if (phy_interrupt_is_valid(phydev)) {
> +		phydev->interrupts = PHY_INTERRUPT_DISABLED;
> +		if (phydev->drv->config_intr)
> +			phydev->drv->config_intr(phydev);

It seems odd going via phydev->drv inside the driver to call functions
which are also inside the driver. Why do you not directly call dp83867_config_intr()?

> +static int dp83867_resume(struct phy_device *phydev)
> +{
> +	genphy_resume(phydev);
> +
> +	/* Enable PHY Interrupts */
> +	if (phy_interrupt_is_valid(phydev)) {
> +		phydev->interrupts = PHY_INTERRUPT_ENABLED;
> +		if (phydev->drv->config_intr)
> +			phydev->drv->config_intr(phydev);
> +	}

Is there a race here? Say the PHY is in a fixed mode, not
autoneg. Could it be, that as soon as you clear the power down bit in
genphy_resume() it signals a link up interrupt? dp83867_config_intr()
then acknowledged and clears that interrupt, before enabling the
interrupt, so the link up event never gets passed to phylib? Maybe the
order needs reversing here?

	   Andrew