netdev - Re: [PATCH net] net: phy: smsc: add missed clk_disable_unprepare in smsc_phy

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Message-ID: <20201116092607.psaelzuga3kcrryu@pengutronix.de>
Date:   Mon, 16 Nov 2020 10:26:07 +0100
From:   Marco Felsch <m.felsch@...gutronix.de>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     Jakub Kicinski <kuba@...nel.org>,
        Zhang Changzhong <zhangchangzhong@...wei.com>, andrew@...n.ch,
        hkallweit1@...il.com, linux@...linux.org.uk, davem@...emloft.net,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH net] net: phy: smsc: add missed clk_disable_unprepare in
 smsc_phy_probe()

On 20-11-14 11:45, Florian Fainelli wrote:
> 
> 
> On 11/14/2020 11:26 AM, Jakub Kicinski wrote:
> > On Thu, 12 Nov 2020 19:23:59 +0800 Zhang Changzhong wrote:
> >> Add the missing clk_disable_unprepare() before return from
> >> smsc_phy_probe() in the error handling case.
> >>
> >> Fixes: bedd8d78aba3 ("net: phy: smsc: LAN8710/20: add phy refclk in support")
> >> Reported-by: Hulk Robot <hulkci@...wei.com>
> >> Signed-off-by: Zhang Changzhong <zhangchangzhong@...wei.com>
> >> ---
> >>  drivers/net/phy/smsc.c | 4 +++-
> >>  1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
> >> index ec97669..0fc39ac 100644
> >> --- a/drivers/net/phy/smsc.c
> >> +++ b/drivers/net/phy/smsc.c
> >> @@ -291,8 +291,10 @@ static int smsc_phy_probe(struct phy_device *phydev)
> >>  		return ret;
> >>  
> >>  	ret = clk_set_rate(priv->refclk, 50 * 1000 * 1000);
> >> -	if (ret)
> >> +	if (ret) {
> >> +		clk_disable_unprepare(priv->refclk);
> >>  		return ret;
> >> +	}
> >>  
> >>  	return 0;
> >>  }
> > 
> > Applied, thanks!
> > 
> > The code right above looks highly questionable as well:
> > 
> >         priv->refclk = clk_get_optional(dev, NULL);
> >         if (IS_ERR(priv->refclk))
> >                 dev_err_probe(dev, PTR_ERR(priv->refclk), "Failed to request clock\n");
> >  
> >         ret = clk_prepare_enable(priv->refclk);
> >         if (ret)
> >                 return ret;
> > 
> > I don't think clk_prepare_enable() will be too happy to see an error
> > pointer. This should probably be:
> > 
> >         priv->refclk = clk_get_optional(dev, NULL);
> >         if (IS_ERR(priv->refclk))
> >                 return dev_err_probe(dev, PTR_ERR(priv->refclk), 
> > 				      "Failed to request clock\n");
> 
> Right, especially if EPROBE_DEFER must be returned because the clock
> provider is not ready yet, we should have a chance to do that.

Hi,

damn.. I missed the return here. Thanks for covering that. Should I send
a fix or did you do that already?

Regards,
  Marco