netdev - Re: [PATCH net] net: phy: fix WoL handling when suspending the PHY

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Message-ID: <20180922164441.GB13316@lunn.ch>
Date:   Sat, 22 Sep 2018 18:44:41 +0200
From:   Andrew Lunn <andrew@...n.ch>
To:     Heiner Kallweit <hkallweit1@...il.com>
Cc:     Florian Fainelli <f.fainelli@...il.com>,
        David Miller <davem@...emloft.net>,
        Realtek linux nic maintainers <nic_swsd@...ltek.com>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH net] net: phy: fix WoL handling when suspending the PHY

On Sat, Sep 22, 2018 at 01:32:55AM +0200, Heiner Kallweit wrote:
> Actually there's nothing wrong with the two changes, they just
> revealed a problem which has been existing before.

Hi Heiner

This is missing a bit of context. Which two changes? I assume you mean
the two Fixes:

> 
> Core of the problem is that phy_suspend() suspends the PHY when it
> should not because of WoL. phy_suspend() checks for WoL already, but
> this works only if the PHY driver handles WoL (what is rarely the case).
> Typically WoL is handled by the MAC driver.
> 
> phylib knows about this and handles it in mdio_bus_phy_may_suspend(),
> but that's used only when suspending the system, not in other cases
> like shutdown.
> 
> This patch basically moves the check for WoL having been activated
> by the MAC driver into phy_suspend(). mdio_bus_phy_resume() now
> resumes the PHY only if it's actually suspended. Also don't do
> anything in phy_suspend() if the PHY is suspended already.
> 
> Last but not least change phy_detach() to call phy_suspend() before
> attached_dev is set to NULL. phy_suspend() accesses attached_dev
> when checking whether the MAC driver activated WoL.

This sounds like it should be multiple patches, not one. Can it be
split, or is there two much inter connectivity? Being able to bisect
could be useful here.

      Thanks
	Andrew