linux-kernel - Re: [PATCH 14/15] net: phy: add PHY regulator support

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Message-ID: <20200623094252.GS1551@shell.armlinux.org.uk>
Date:   Tue, 23 Jun 2020 10:42:52 +0100
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Andrew Lunn <andrew@...n.ch>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        devicetree <devicetree@...r.kernel.org>,
        Vladimir Oltean <vladimir.oltean@....com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Fabien Parent <fparent@...libre.com>,
        Iyappan Subramanian <iyappan@...amperecomputing.com>,
        Quan Nguyen <quan@...amperecomputing.com>,
        Frank Rowand <frowand.list@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Andrew Perepech <andrew.perepech@...iatek.com>,
        Stephane Le Provost <stephane.leprovost@...iatek.com>,
        Keyur Chudgar <keyur@...amperecomputing.com>,
        Jassi Brar <jaswinder.singh@...aro.org>,
        Claudiu Manoil <claudiu.manoil@....com>,
        Mark Brown <broonie@...nel.org>,
        "moderated list:ARM/Mediatek SoC..." 
        <linux-mediatek@...ts.infradead.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        netdev <netdev@...r.kernel.org>,
        Ilias Apalodimas <ilias.apalodimas@...aro.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Pedro Tsai <pedro.tsai@...iatek.com>,
        "David S . Miller" <davem@...emloft.net>,
        Heiner Kallweit <hkallweit1@...il.com>
Subject: Re: [PATCH 14/15] net: phy: add PHY regulator support

On Tue, Jun 23, 2020 at 11:41:11AM +0200, Bartosz Golaszewski wrote:
> pon., 22 cze 2020 o 15:29 Russell King - ARM Linux admin
> <linux@...linux.org.uk> napisał(a):
> >
> 
> [snip!]
> 
> >
> > This is likely to cause issues for some PHY drivers.  Note that we have
> > some PHY drivers which register a temperature sensor in the probe
> > function, which means they can be accessed independently of the lifetime
> > of the PHY bound to the network driver (which may only be while the
> > network device is "up".)  We certainly do not want hwmon failing just
> > because the network device is down.
> >
> > That's kind of worked around for the reset stuff, because there are two
> > layers to that: the mdio device layer reset support which knows nothing
> > of the PHY binding state to the network driver, and the phylib reset
> > support, but it is not nice.
> >
> 
> Regulators are reference counted so if the hwmon driver enables it
> using mdio_device_power_on() it will stay on even after the PHY driver
> calls phy_device_power_off(), right? Am I missing something?

If that is true, you will need to audit the PHY drivers to add that.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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