Re: [PATCH v8 10/26] memory: tegra30-emc: Factor out clk initialization

From: Krzysztof Kozlowski <krzk@kernel.org>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Georgi Djakov <georgi.djakov@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	MyungJoo Ham <myungjoo.ham@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Chanwoo Choi <cw00.choi@samsung.com>,
	Mikko Perttunen <cyndis@kapsi.fi>,
	Viresh Kumar <vireshk@kernel.org>,
	Peter Geis <pgwipeout@gmail.com>,
	Nicolas Chauvet <kwizart@gmail.com>,
	linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v8 10/26] memory: tegra30-emc: Factor out clk initialization
Date: Wed, 11 Nov 2020 09:52:50 +0100	[thread overview]
Message-ID: <20201111085250.GA11589@kozik-lap> (raw)
In-Reply-To: <20201111085115.GA4050@kozik-lap>

On Wed, Nov 11, 2020 at 09:51:15AM +0100, Krzysztof Kozlowski wrote:
> On Wed, Nov 11, 2020 at 04:14:40AM +0300, Dmitry Osipenko wrote:
> > Factor out clk initialization and make it resource-managed. This makes
> > easier to follow code and will help to make further changes cleaner.
> > 
> > Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> > ---
> >  drivers/memory/tegra/tegra30-emc.c | 70 ++++++++++++++++++++----------
> >  1 file changed, 47 insertions(+), 23 deletions(-)
> > 
> > diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
> > index d27df842a667..1df42e212d73 100644
> > --- a/drivers/memory/tegra/tegra30-emc.c
> > +++ b/drivers/memory/tegra/tegra30-emc.c
> > @@ -1550,6 +1550,49 @@ static int tegra_emc_opp_table_init(struct tegra_emc *emc)
> >  	return err;
> >  }
> >  
> > +static void devm_tegra_emc_unset_callback(void *data)
> > +{
> > +	tegra20_clk_set_emc_round_callback(NULL, NULL);
> > +}
> > +
> > +static void devm_tegra_emc_unreg_clk_notifier(void *data)
> > +{
> > +	struct tegra_emc *emc = data;
> > +
> > +	clk_notifier_unregister(emc->clk, &emc->clk_nb);
> > +}
> > +
> > +static int tegra_emc_init_clk(struct tegra_emc *emc)
> > +{
> > +	int err;
> > +
> > +	tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
> > +
> > +	err = devm_add_action_or_reset(emc->dev, devm_tegra_emc_unset_callback,
> > +				       NULL);
> > +	if (err)
> > +		return err;
> > +
> > +	emc->clk = devm_clk_get(emc->dev, NULL);
> > +	if (IS_ERR(emc->clk)) {
> > +		dev_err(emc->dev, "failed to get EMC clock: %pe\n", emc->clk);
> > +		return PTR_ERR(emc->clk);
> > +	}
> > +
> > +	err = clk_notifier_register(emc->clk, &emc->clk_nb);
> > +	if (err) {
> > +		dev_err(emc->dev, "failed to register clk notifier: %d\n", err);
> > +		return err;
> > +	}
> > +
> > +	err = devm_add_action_or_reset(emc->dev,
> > +				       devm_tegra_emc_unreg_clk_notifier, emc);
> > +	if (err)
> > +		return err;
> > +
> > +	return 0;
> > +}
> > +
> >  static int tegra_emc_probe(struct platform_device *pdev)
> >  {
> >  	struct device_node *np;
> > @@ -1599,25 +1642,13 @@ static int tegra_emc_probe(struct platform_device *pdev)
> >  		return err;
> >  	}
> >  
> > -	tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
> > -
> > -	emc->clk = devm_clk_get(&pdev->dev, "emc");
> > -	if (IS_ERR(emc->clk)) {
> > -		err = PTR_ERR(emc->clk);
> > -		dev_err(&pdev->dev, "failed to get emc clock: %d\n", err);
> > -		goto unset_cb;
> > -	}
> > -
> > -	err = clk_notifier_register(emc->clk, &emc->clk_nb);
> > -	if (err) {
> > -		dev_err(&pdev->dev, "failed to register clk notifier: %d\n",
> > -			err);
> > -		goto unset_cb;
> > -	}
> > +	err = tegra_emc_init_clk(emc);
> > +	if (err)
> > +		return err;
> >  
> >  	err = tegra_emc_opp_table_init(emc);
> >  	if (err)
> > -		goto unreg_notifier;
> > +		return err;
> >  
> >  	platform_set_drvdata(pdev, emc);
> >  	tegra_emc_rate_requests_init(emc);
> > @@ -1632,13 +1663,6 @@ static int tegra_emc_probe(struct platform_device *pdev)
> >  	try_module_get(THIS_MODULE);
> >  
> >  	return 0;
> > -
> > -unreg_notifier:
> > -	clk_notifier_unregister(emc->clk, &emc->clk_nb);
> 
> You added this code in patch #8, so adding-and-removing a piece of code

Correction: you added this in patch #9.

Best regards,
Krzysztof

> is a nice hint that this patch should be before. Don't add new code
> which later you simplify. Move all bugfixes and all simplifications to
> beginning of patchset.
> 
> That's quite similar case to v6 where you put bugfixes in the middle
> of patchset.
> 