linux-kernel - Re: [PATCH V3] soc: imx8m: Unregister cpufreq and soc dev in cleanup path

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Message-ID: <20250214063004.jvz5vukaxszcucd7@pengutronix.de>
Date: Fri, 14 Feb 2025 07:30:04 +0100
From: Marco Felsch <m.felsch@...gutronix.de>
To: Peng Fan <peng.fan@....nxp.com>
Cc: shawnguo@...nel.org, s.hauer@...gutronix.de, kernel@...gutronix.de,
	festevam@...il.com, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, marex@...x.de,
	Peng Fan <peng.fan@....com>
Subject: Re: [PATCH V3] soc: imx8m: Unregister cpufreq and soc dev in cleanup
 path

Hi Peng,

On 25-02-14, Peng Fan wrote:
> Hi Shawn,
> 
> On Thu, Dec 19, 2024 at 10:50:29PM +0800, Peng Fan (OSS) wrote:
> >From: Peng Fan <peng.fan@....com>
> >
> >Unregister the cpufreq device and soc device when resource unwinding,
> >otherwise there will be warning when do removing test:
> >sysfs: cannot create duplicate filename '/devices/platform/imx-cpufreq-dt'
> >CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.13.0-rc1-next-20241204
> >Hardware name: NXP i.MX8MPlus EVK board (DT)
> >
> >Fixes: 9cc832d37799 ("soc: imx8m: Probe the SoC driver as platform driver")
> >Cc: Marco Felsch <m.felsch@...gutronix.de>
> >Signed-off-by: Peng Fan <peng.fan@....com>
> >---
> 
> Any comments?
> 
> Thanks,
> Peng
> 
> >
> >V3:
> > Per Marco, drop remove function, use devm_add_action and update the patch
> > title accordingly.
> >
> >V2:
> > Add err check when create the cpufreq platform device
> > https://lore.kernel.org/all/20241217015826.1374497-1-peng.fan@oss.nxp.com/

This is got lost. Albeit platform_device_unregister() can handle
IS_ERROR() cases I don't like the fact that we do not return the error
if there is any during probe. Please see below.

> >
> > drivers/soc/imx/soc-imx8m.c | 23 +++++++++++++++++++++--
> > 1 file changed, 21 insertions(+), 2 deletions(-)
> >
> >diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
> >index 8ac7658e3d52..585631b7ae44 100644
> >--- a/drivers/soc/imx/soc-imx8m.c
> >+++ b/drivers/soc/imx/soc-imx8m.c
> >@@ -192,9 +192,20 @@ static __maybe_unused const struct of_device_id imx8_soc_match[] = {
> > 	devm_kasprintf((dev), GFP_KERNEL, "%d.%d", ((soc_rev) >> 4) & 0xf, (soc_rev) & 0xf) : \
> > 	"unknown"
> > 
> >+static void imx8m_unregister_soc(void *data)
> >+{
> >+	soc_device_unregister(data);
> >+}
> >+
> >+static void imx8m_unregister_cpufreq(void *data)
> >+{
> >+	platform_device_unregister(data);
> >+}
> >+
> > static int imx8m_soc_probe(struct platform_device *pdev)
> > {
> > 	struct soc_device_attribute *soc_dev_attr;
> >+	struct platform_device *cpufreq_dev;
> > 	const struct imx8_soc_data *data;
> > 	struct device *dev = &pdev->dev;
> > 	const struct of_device_id *id;
> >@@ -239,11 +250,19 @@ static int imx8m_soc_probe(struct platform_device *pdev)
> > 	if (IS_ERR(soc_dev))
> > 		return PTR_ERR(soc_dev);
> > 
> >+	ret = devm_add_action(dev, imx8m_unregister_soc, soc_dev);
> >+	if (ret)
> >+		return ret;
> >+
> > 	pr_info("SoC: %s revision %s\n", soc_dev_attr->soc_id,
> > 		soc_dev_attr->revision);
> > 
> >-	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
> >-		platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
> >+	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT)) {
> >+		cpufreq_dev = platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
		if (IS_ERROR(cpufreq_dev))
			return dev_err_probe(dev, "Failed to imx-cpufreq-dev device\n",
					     PTR_ERR(cpufreq_dev));

Regards,
  Marco

> >+		ret = devm_add_action(dev, imx8m_unregister_cpufreq, cpufreq_dev);
> >+		if (ret)
> >+			return ret;
> >+	}
> > 
> > 	return 0;
> > }
> >-- 
> >2.37.1
> >
> >
>