netdev - Re: [PATCH 2/2] net: phy: Ensure the MDIO bus module is held

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Message-ID: <20140723184041.GA24850@arch.cereza>
Date:	Wed, 23 Jul 2014 15:40:41 -0300
From:	Ezequiel Garcia <ezequiel.garcia@...e-electrons.com>
To:	Florian Fainelli <f.fainelli@...il.com>
Cc:	netdev <netdev@...r.kernel.org>,
	David Miller <davem@...emloft.net>,
	Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>,
	Gregory Clement <gregory.clement@...e-electrons.com>
Subject: Re: [PATCH 2/2] net: phy: Ensure the MDIO bus module is held

On 23 Jul 11:22 AM, Florian Fainelli wrote:
> 2014-07-22 17:16 GMT-07:00 Ezequiel Garcia <ezequiel.garcia@...e-electrons.com>:
> > @@ -614,10 +623,14 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
> >          */
> >         err = phy_init_hw(phydev);
> >         if (err)
> > -               phy_detach(phydev);
> > -       else
> > -               phy_resume(phydev);
> > +               goto err_module_put;
> >
> > +       phy_resume(phydev);
> > +       return err;
> > +
> > +err_module_put:
> > +       module_put(bus_module);
> > +       phy_detach(phydev);
> 
> Since we are calling phy_detach() which is also attempting to do a
> module_put(), does not that result in one too many calls to
> module_put() on error path?
> 

As far as I can see all that module_get() and module_put() do
is increment and decrement refcounters. Therefore, I think you can
have as many module_{get,put}() calls as you want on a path.
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com
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