From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Subject: Re: [RFC 0/2] net: phy: Prevent an MDIO bus from being unloaded
 while in use
Date: Mon, 21 Jul 2014 15:55:53 -0300
Message-ID: <20140721185552.GA20027@arch.cereza>
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Cc: netdev <netdev@vger.kernel.org>,
	David Miller <davem@davemloft.net>,
	Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	Gregory Clement <gregory.clement@free-electrons.com>
To: Florian Fainelli <f.fainelli@gmail.com>
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Hi Florian,

Thanks for the quick reply.

On 21 Jul 11:42 AM, Florian Fainelli wrote:
[..]
> >
> > This patchset fixes this by calling module_{get,put} in the etherne=
t driver.
> > After this patch, the mvmdio driver is no longer removable:
> >
> >   $ modprobe -r mvmdio
> >   modprobe: can't unload module mvmdio: Resource temporarily unavai=
lable
> >
> > Of course, we can expect a few drivers to have the same need and th=
erefore
> > we could argue about moving this to be part of the phydev connectio=
n.
>=20
> Right, that's exactly what jumps to mind when I take a look at your
> patch set. As long as a PHY device connected to a particular MDIO bus
> is in used, we should make sure its refcount does not hit zero.
>=20

Any suggestions about where to do it? I think the right place is
after the calls to bus_find_device() in of_phy_find_device() and
phy_connect().

> BTW, neither mvmdio nor mvneta seems to set their 'owner' field, is
> that intentional?
>=20

Actually, I had a patch that did so and then dropped it. The owner
is set to unconditionally for plaftorm drivers, so setting it has no
effect. See include/linux/platform_device.h:

/*
 * use a macro to avoid include chaining to get THIS_MODULE
 */
#define platform_driver_register(drv) \
        __platform_driver_register(drv, THIS_MODULE)

--=20
Ezequiel Garc=EDa, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com