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Message-ID: <7686403c-7252-ef7a-70fc-040c5ab8cb79@linux.intel.com>
Date:   Thu, 28 Jul 2022 11:53:33 -0500
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Subject: Re: [PATCH v2 1/3] drivers: misc: intel_sysid: Add sysid from arch to
 drivers
Content-Language: en-US
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     kah.jing.lee@intel.com, linux-kernel@vger.kernel.org,
        arnd@arndb.de, rafael.j.wysocki@intel.com, tien.sung.ang@intel.com,
        dinh.nguyen@intel.com, Zhou@kroah.com,
        Furong <furong.zhou@intel.com>, Vinod Koul <vkoul@kernel.org>,
        Bard Liao <yung-chuan.liao@linux.intel.com>
References: <20220721123017.416438-1-kah.jing.lee@intel.com>
 <20220721123149.416618-1-kah.jing.lee@intel.com> <YuJAll2MEgKF0MVM@kroah.com>
 <be3f189e-c17c-2438-450d-3d84dfcd71da@linux.intel.com>
 <YuKyTKHk3c7DibX3@kroah.com>
From:   Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
In-Reply-To: <YuKyTKHk3c7DibX3@kroah.com>
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On 7/28/22 10:59, Greg KH wrote:
> On Thu, Jul 28, 2022 at 10:37:37AM -0500, Pierre-Louis Bossart wrote:
>> Thanks for the review Greg,
>>
>>>> +static int intel_sysid_probe(struct platform_device *pdev)
>>>> +{
>>>> +	struct intel_sysid *sysid;
>>>> +	struct resource	*regs;
>>>> +
>>>> +	sysid = devm_kzalloc(&pdev->dev, sizeof(struct intel_sysid),
>>>> +		GFP_KERNEL);
>>>> +	if (!sysid)
>>>> +		return -ENOMEM;
>>>> +
>>>> +	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>>> +	if (!regs)
>>>> +		return -ENXIO;
>>>> +
>>>> +	sysid->regs = devm_ioremap_resource(&pdev->dev, regs);
>>>> +	if (IS_ERR(sysid->regs))
>>>> +		return PTR_ERR(sysid->regs);
>>>> +
>>>> +	platform_set_drvdata(pdev, sysid);
>>>> +
>>>> +	return devm_device_add_group(&pdev->dev, &intel_sysid_attr_group);
>>>
>>> You just raced with userspace and lost.  Please use the default group
>>> for the platform device.
>>>
>>> I need to go remove this function, it should not be used at all as it is
>>> broken.
>>
>> Can you elaborate on the issue and suggested replacement?
>>
>> We used this function for the SoundWire sysfs based on your review
>> comments (2 years ago?) that we should not muck with kobj, and that
>> function devm_device_add_group() is also used in a probe function.
> 
> Use the default_groups pointer in the driver structure.

did you mean dev_groups?

I am not following the idea, for SoundWire all the attributes are really
device-specific or described by ACPI and cannot be hard-coded in the
driver structure.