RE: [PATCH V4] thermal: imx: fix for dependency on cpu-freq

[Anson Huang]

Best Regards!
Anson Huang

> -----Original Message-----
> From: Viresh Kumar [mailto:viresh.kumar@xxxxxxxxxx]
> Sent: 2018年11月21日 13:21
> To: Anson Huang <anson.huang@xxxxxxx>
> Cc: rui.zhang@xxxxxxxxx; edubezval@xxxxxxxxx; daniel.lezcano@xxxxxxxxxx;
> linux-pm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> l.stach@xxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>
> Subject: Re: [PATCH V4] thermal: imx: fix for dependency on cpu-freq
> 
> On 21-11-18, 05:08, Anson Huang wrote:
> > The thermal driver is a standalone driver for monitoring SoC
> > temperature by enabling thermal sensor, so it can be enabled even when
> > CONFIG_CPU_FREQ is NOT set. So remove the dependency with
> CPU_THERMAL.
> >
> > Introduce dummy function of legacy cooling register/unregister to make
> > thermal driver probe successfully when CONFIG_CPU_FREQ is NOT set.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> > ---
> > changes since V3:
> > 	rename the label of "cpufreq_put" with "legacy_cleanup".
> >  drivers/thermal/Kconfig       |  2 +-
> >  drivers/thermal/imx_thermal.c | 44
> > +++++++++++++++++++++++++++++++------------
> >  2 files changed, 33 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index
> > 5422523..93bd3bb 100644
> > --- a/drivers/thermal/Kconfig
> > +++ b/drivers/thermal/Kconfig
> > @@ -212,7 +212,7 @@ config HISI_THERMAL
> >
> >  config IMX_THERMAL
> >  	tristate "Temperature sensor driver for Freescale i.MX SoCs"
> > -	depends on (ARCH_MXC && CPU_THERMAL) || COMPILE_TEST
> > +	depends on ARCH_MXC || COMPILE_TEST
> >  	depends on NVMEM || !NVMEM
> >  	depends on MFD_SYSCON
> >  	depends on OF
> > diff --git a/drivers/thermal/imx_thermal.c
> > b/drivers/thermal/imx_thermal.c index 1566154..328ee05 100644
> > --- a/drivers/thermal/imx_thermal.c
> > +++ b/drivers/thermal/imx_thermal.c
> > @@ -648,15 +648,24 @@ static const struct of_device_id
> > of_imx_thermal_match[] = {  };  MODULE_DEVICE_TABLE(of,
> > of_imx_thermal_match);
> >
> > +#ifdef CONFIG_CPU_FREQ
> >  /*
> >   * Create cooling device in case no #cooling-cells property is available in
> >   * CPU node
> >   */
> >  static int imx_thermal_register_legacy_cooling(struct
> > imx_thermal_data *data)  {
> > -	struct device_node *np = of_get_cpu_node(data->policy->cpu, NULL);
> > +	struct device_node *np;
> >  	int ret;
> >
> > +	data->policy = cpufreq_cpu_get(0);
> > +	if (!data->policy) {
> > +		pr_debug("%s: CPUFreq policy not found\n", __func__);
> > +		return -EPROBE_DEFER;
> > +	}
> > +
> > +	np = of_get_cpu_node(data->policy->cpu, NULL);
> > +
> >  	if (!np || !of_find_property(np, "#cooling-cells", NULL)) {
> >  		data->cdev = cpufreq_cooling_register(data->policy);
> >  		if (IS_ERR(data->cdev)) {
> > @@ -669,6 +678,22 @@ static int
> imx_thermal_register_legacy_cooling(struct imx_thermal_data *data)
> >  	return 0;
> >  }
> >
> > +static void imx_thermal_unregister_legacy_cooling(struct
> > +imx_thermal_data *data) {
> > +	cpufreq_cooling_unregister(data->cdev);
> > +	cpufreq_cpu_put(data->policy);
> > +}
> > +#else
> > +static inline int imx_thermal_register_legacy_cooling(struct
> > +imx_thermal_data *data) {
> > +	return 0;
> > +}
> > +
> > +static inline void imx_thermal_unregister_legacy_cooling(struct
> > +imx_thermal_data *data) { } #endif
> > +
> >  static int imx_thermal_probe(struct platform_device *pdev)  {
> >  	struct imx_thermal_data *data;
> > @@ -743,13 +768,9 @@ static int imx_thermal_probe(struct
> platform_device *pdev)
> >  	regmap_write(map, data->socdata->sensor_ctrl + REG_SET,
> >  		     data->socdata->power_down_mask);
> >
> > -	data->policy = cpufreq_cpu_get(0);
> > -	if (!data->policy) {
> > -		pr_debug("%s: CPUFreq policy not found\n", __func__);
> > -		return -EPROBE_DEFER;
> > -	}
> > -
> >  	ret = imx_thermal_register_legacy_cooling(data);
> > +	if (ret == -EPROBE_DEFER)
> > +		return ret;
> >  	if (ret) {
> 
> Sorry for not noticing earlier, but wouldn't it be better to move the
> EPROBE_DEFER check inside of this if block ? Otherwise we will have two
> conditional blocks in the success (normal) case.

Since there is similar case of DEFER PROBE for the case of imx_init_from_nvmem_cells
check, should I create another patch of same fix for it in V5 patch set?

Anson.

> 
> Something like this:
> 
> if (ret) {
>         if (ret == -EPROBE_DEFER)
>                 return ret;
> 
>         dev_err(..);
>         ...
> }
> 
> >  		dev_err(&pdev->dev,
> >  			"failed to register cpufreq cooling device: %d\n", ret); @@
> -762,7
> > +783,7 @@ static int imx_thermal_probe(struct platform_device *pdev)
> >  		if (ret != -EPROBE_DEFER)
> >  			dev_err(&pdev->dev,
> >  				"failed to get thermal clk: %d\n", ret);
> > -		goto cpufreq_put;
> > +		goto legacy_cleanup;
> >  	}
> >
> >  	/*
> > @@ -775,7 +796,7 @@ static int imx_thermal_probe(struct platform_device
> *pdev)
> >  	ret = clk_prepare_enable(data->thermal_clk);
> >  	if (ret) {
> >  		dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
> > -		goto cpufreq_put;
> > +		goto legacy_cleanup;
> >  	}
> >
> >  	data->tz = thermal_zone_device_register("imx_thermal_zone",
> > @@ -829,9 +850,8 @@ static int imx_thermal_probe(struct platform_device
> *pdev)
> >  	thermal_zone_device_unregister(data->tz);
> >  clk_disable:
> >  	clk_disable_unprepare(data->thermal_clk);
> > -cpufreq_put:
> > -	cpufreq_cooling_unregister(data->cdev);
> > -	cpufreq_cpu_put(data->policy);
> > +legacy_cleanup:
> > +	imx_thermal_unregister_legacy_cooling(data);
> >
> >  	return ret;
> >  }
> > --
> > 2.7.4
> 
> --
> viresh