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

Pierre-Louis Bossart
2022-07-28T16:53:40Z

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.