Messages in this thread | | | Date | Fri, 29 Jul 2022 13:56:25 +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 Fri, Jul 29, 2022 at 01:43:55PM +0200, Greg KH wrote: > 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.
In looking at your attribute code, ick, you dynamically create a ton of them. But for the ones that you do not, you can just have the driver core add them. Let me make up a patch that shows what I am thinking of...
thanks,
greg k-h
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