Messages in this thread | | | Date | Fri, 29 Jul 2022 13:43:55 +0200 | From | Greg KH <> | Subject | Re: [PATCH v2 1/3] drivers: misc: intel_sysid: Add sysid from arch to drivers |
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On Thu, Jul 28, 2022 at 11:53:33AM -0500, Pierre-Louis Bossart wrote: > > > 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?
Yes, sorry, that's the correct name.
> 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.
That's what the is_visible() callback is for in the groups structure, you determine if the attribute is visable or not at runtime, you don't rely on the driver itself to add/remove attributes, that does not scale and again, is racy.
thanks,
greg k-h
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