2020. december 27., vasárnap 23:27 keltezéssel, Roderick Colenbrander írta:

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-       ret = sysfs_create_group(&hdev->dev.kobj, &ps_device_attribute_group);

It's a minor thing, but I think `device_{add,remove}_group()` would be better
here in the sense that it expresses the fact that the group is added to a device,
not just any object better.

Agreed, that's nicer I wasn't aware of it. I try to follow what other
hid drivers do and they all used the kobj directly, which honestly
felt nasty. Will change it to this.

Actually devm_device_add_group seems to be even nicer. Surprisingly it
isn't widely used yet.

Roderick

Well, indeed, although I believe that shouldn't be used here. Consider
what happens if the hid-playstation module is unloaded. The attributes
of the HID device will not be unregistered, but the backing functions/etc.
are unloaded, so reading/writing them will have undesirable effects - I imagine.
So in either case, you'll need to use `[devm_]device_remove_group()`, and for
that reason I think using the devm_* variant is less efficient.
Please note, that I am not 100% sure this hypothesis is correct, but I'm pretty sure.


Regards,
Barnabás Pőcze