Re: [PATCH v2 1/3] drivers: misc: intel_sysid: Add sysid from arch to drivers

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

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.