Re: [PATCH v3 5/8] platform/chrome: Introduce cros_ec_device_alloc()

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Jul 24, 2025 at 09:58:39AM +0000, Tzung-Bi Shih wrote:
> On Mon, Jul 21, 2025 at 08:15:07AM +0200, Greg KH wrote:
> > On Mon, Jul 21, 2025 at 04:44:53AM +0000, Tzung-Bi Shih wrote:
> > > Prepare to decouple the lifecycle of struct cros_ec_device from specific
> > > device by introducing a kref.
> > 
> > Ick, are you sure?  This is a device, so use struct device for it.
> > That's what it is there for.
> > 
> > So shouldn't this be its own 'struct device' and let the driver core
> > handle it correctly instead of trying to have a "child" structure with a
> > reference count that is not shown in sysfs at all?
> 
> Thanks for the review.
> 
> To make sure I understand, do the following patches (draft and simplified) make
> sense?  Short summary:
> - cros_ec_device_alloc() allocates resources and setup the destructor.
> - cros_ec_register() adds the device to the device hierarchy.
> - cros_ec_unregister() removes the device.
> - cros_ec_chardev_open() gets a refcount of the device.
> - cros_ec_chardev_release() puts the refcount.

NEVER attempt to increment/decrement refcounts on open/release.  That
way lies madness and should not be needed at all, the underlying
infrastructure should keep things working properly here, right?

thanks,

greg k-h