Re: [RFC net-next 0/7] Provide an ism layer

Andrew Lunn
2025-01-17T15:10:26Z

On Fri, Jan 17, 2025 at 02:00:55PM +0100, Alexandra Winter wrote:
>
>
> On 17.01.25 03:13, Dust Li wrote:
> >>>> Modular Approach: I've made the ism_loopback an independent kernel
> >>>> module since dynamic enable/disable functionality is not yet supported
> >>>> in SMC. Using insmod and rmmod for module management could provide the
> >>>> flexibility needed in practical scenarios.
> >>
> >> With this proposal ism_loopback is just another ism device and SMC-D will
> >> handle removal just like ism_client.remove(ism_dev) of other ism devices.
> >>
> >> But I understand that net/smc/ism_loopback.c today does not provide enable/disable,
> >> which is a big disadvantage, I agree. The ism layer is prepared for dynamic
> >> removal by ism_dev_unregister(). In case of this RFC that would only happen
> >> in case of rmmod ism. Which should be improved.
> >> One way to do that would be a separate ism_loopback kernel module, like you say.
> >> Today ism_loopback is only 10k LOC, so I'd be fine with leaving it in the ism module.
> >> I also think it is a great way for testing any ISM client, so it has benefit for
> >> anybody using the ism module.
> >> Another way would be e.g. an 'enable' entry in the sysfs of the loopback device.
> >> (Once we agree if and how to represent ism devices in genera in sysfs).
> > This works for me as well. I think it would be better to implement this
> > within the common ISM layer, rather than duplicating the code in each
> > device. Similar to how it's done in netdevice.
> >
> > Best regards,
> > Dust
>
>
> Is there a specific example for enable/disable in the netdevice code, you have in mind?
> Or do you mean in general how netdevice provides a common layer?
> Yes, everything that is common for all devices should be provided by the network layer.

Again, lack of basic understanding.... but why is it not a network
device? Network devices are not just Ethernet. We also have CAN, SLIP,
FDDI, etc.

Andrew