On Fri, Sep 12, 2025 at 4:40 PM Greg Kroah-Hartman
[off-list ref] wrote:

Dan's proposal here is a good start, but the "sleep in cdev_del() until
the device drains all existing opens" is going to not really work well
for what we want.

So sure, make a new cdev api to use this, that's fine, then we will have
what, 5 different ways to use a cdev?  :)

Seriously, that would be good, then we can work to convert things over,
but I think overall it will look much the same as what patch 5/5 does
here.  But details matter, I don't really known for sure...

Either way, I think this patch series stands on its own, it doesn't
require cdev to implement it, drivers can use it to wrap a cdev if they
want to.  We have other structures that want to do this type of thing
today as is proof with the rust implementation for the devm api.

Yeah, I'm not against this going upstream. If more development is
needed for this to be usable in other parts of the kernel, that can be
done gradually. Literally no subsystem ever was perfect on day 1.

Tzung-Bi: I'm not sure if you did submit anything but I'd love to see
this discussed during Linux Plumbers in Tokyo, it's the perfect fit
for the kernel summit.

Bartosz