From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gregory CLEMENT <gregory.clement@free-electrons.com>
Subject: Re: [PATCH v2] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock
Date: Mon, 02 Oct 2017 16:32:23 +0200
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References: <20170929130435.6805-1-gregory.clement@free-electrons.com>
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        <20170930141753.7c4e34ea@xhacker.debian>
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In-Reply-To: <20170930141753.7c4e34ea@xhacker.debian> (Jisheng Zhang's message
        of "Sat, 30 Sep 2017 14:17:53 +0800")
Sender: stable-owner@vger.kernel.org
To: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>, Ulf Hansson <ulf.hansson@linaro.org>, Adrian Hunter <adrian.hunter@intel.com>, linux-mmc@vger.kernel.org, Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org, Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>, Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>, linux-arm-kernel@lists.infradead.org, Antoine Tenart <antoine.tenart@free-electrons.com>, =?utf-8?Q?Miqu=C3=A8l?= Raynal <miquel.raynal@free-electrons.com>, Nadav Haklai <nadavh@marvell.com>, Shadi Ammouri <shadi@marvell.com>, Yehuda Yitschak <yehuday@marvell.com>, Omri Itach <omrii@marvell.com>, Hanna Hawa <hannah@marvell.com>, Igal Liberman <igall@marvell.com>, Marcin Wojtas <mw@semihalf.com>, Stabl
List-Id: linux-mmc@vger.kernel.org

Hi Jisheng,
 
 On sam., sept. 30 2017, Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote:

> Hi Thomas,
>
> On Sat, 30 Sep 2017 08:07:10 +0200 Thomas Petazzoni wrote:
>
>> Hello,
>> 
>> On Sat, 30 Sep 2017 10:41:09 +0800, Jisheng Zhang wrote:
>> 
>> > > +	priv->axi_clk = devm_clk_get(&pdev->dev, "axi");
>> > > +	if (IS_ERR(priv->axi_clk)) {
>> > > +		err = PTR_ERR(priv->axi_clk);
>> > > +		if (err == -EPROBE_DEFER)
>> > > +			goto err_clk;
>> > > +		priv->axi_clk = NULL;    
>> > 
>> > IMHO, this assignment could be removed. What do you think?  
>> 
>> No, because if the clock is not present in the Device Tree,
>> priv->axi_clk will contain an error code encoded as a pointer, so
>> priv->axi_clk will not be NULL. Hence the rest of the code that will
>
> FWICT, the clk_disable_unprepare() could also check whether the clk
> is err, am I wrong?

You're right, I've jsut checked it.
So I will remove it to have a smaller fix.

Thanks,

Gregory

>
>> operate on this clock will believe there is a valid clock pointed by
>> priv->axi_clk. So we really want to reset it to NULL when there was an
>> error getting the clock.
>> 
>> Best regards,
>> 
>> Thomas
>

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com