Re: [PATCH v1 04/10] ACPI: processor: thermal: Use thermal_cooling_device_create()

[Rafael J. Wysocki (Intel)]

On Fri, Sep 11, 2026 at 6:32 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Fri, Sep 11, 2026 at 03:02:53PM +0200, Rafael J. Wysocki wrote:
>
> > Instead of using thermal_cooling_device_register() for registering
> > a cooling device in the ACPI processor driver, make it use
> > thermal_cooling_device_create() and pass a pointer to the processor
> > device representing the given CPU to that function as the cooling
> > device's parent.  That will cause the cooling device's sysfs directory
> > to be created under the parent's sysfs directory (among other things).
> >
> > Since creating a class device under a parent causes a "device" symbolic
> > link from the sysfs directory of the class device to the sysfs directory
> > of the parent to appear automatically, remove the code creating the
> > "device" symbolic link from the sysfs directory of the cooling device
> > in question to the sysfs directory of the parent's companion ACPI
> > device.  That ACPI device is reachable through the "firmware_node"
> > symbolic link in the parent's sysfs directory regardless.
> >
> > Moreover, since the cooling device is now located in sysfs under its
> > parent and it can be easily identified as a cooling device, there is
> > no need to create a "thermal_cooling" symbolic link from its parent's
> > ACPI companion to it.  Accordingly, also remove the code creating that
> > symbolic link.
> >
> > While at it, check for error pointer values in addition to checking
> > for NULL in acpi_processor_thermal_exit() to avoid dereferncing them
>
> Typo: dereferencing

Noted, thanks!

> > mistakenly.
>
> ...
>
> Is any user space ABI breakage expected as an outcome of this change?

Not really.