Re: [PATCHv3 2/3] optee: use uuid for sysfs driver entry

From: Maxim Uvarov
Date: Mon May 25 2020 - 09:33:56 EST


On Mon, 25 May 2020 at 15:47, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Mon, May 25, 2020 at 02:52:34PM +0300, Maxim Uvarov wrote:
> > Optee device names for sysfs needed to be unique
> > and it's better if they will mean something. UUID for name
> > looks like good solution:
> > /sys/bus/tee/devices/optee-clnt-<uuid>
>
> Can you document that in Documentation/ABI/ ?
>
yes, sure if we agree to go with uuid.

> And why UUID? Those are usually huge, is that easier than just a unique
> number?
>

UUID here is connected to Trusted Application (TA) in a secure world.
If you need to 'find' sysfs entry for the corresponding driver
becomes very easy.
Also UUID here are not really huge, like:
/sys/bus/tee/devices/optee-clnt-71d950bc-c9d4-c442-82cb-343fb7f37896
/sys/bus/tee/devices/optee-clnt-ba3ac5b6-6996-6846-a7f2-205629d00f86

I think that is better then optee-clnt-0, optee-clnt-1.. which can be
reordered on each boot and does not carry any information. And on
module unload there will be missing numbers.

Regards,
Maxim.

> thanks,
>
> greg k-h