Hello, On Tue, Dec 16, 2025 at 01:08:38PM +0530, Sumit Garg wrote: > On Mon, Dec 15, 2025 at 3:02 PM Uwe Kleine-König > <[email protected]> wrote: > > On Mon, Dec 15, 2025 at 04:54:11PM +0900, Sumit Garg wrote: > > > Feel free to make the tee_bus_type private as the last patch in the series > > > such that any followup driver follows this clean approach. > > > > There is a bit more to do for that than I'm willing to invest. With my > > patch series applied `tee_bus_type` is still used in > > drivers/tee/optee/device.c and drivers/tee/tee_core.c. > > Oh I see, I guess we need to come with some helpers around device > register/unregister from TEE subsystem as well. Let's plan that for a > followup patch-set, I don't want this patch-set to be bloated more.
Don't consider me in for that. But it sounds like a nice addition.
> > Maybe it's
> > sensible to merge these two files into a single one.
>
> It's not possible as the design for TEE bus is to have TEE
> implementation drivers like OP-TEE, AMD-TEE, TS-TEE, QTEE and so on to
> register devices on the bus.
So only OP-TEE uses the bus for devices and the other *-TEE don't. Also
sounds like something worth to be fixed.
> > The things I wonder about additionally are:
> >
> > - if CONFIG_OPTEE=n and CONFIG_TEE=y|m the tee bus is only used for
> > drivers but not devices.
>
> Yeah since the devices are rather added by the TEE implementation driver.
>
> >
> > - optee_register_device() calls device_create_file() on
> > &optee_device->dev after device_register(&optee_device->dev).
> > (Attention half-knowledge!) I think device_create_file() should not
> > be called on an already registered device (or you have to send a
> > uevent afterwards). This should probably use type attribute groups.
> > (Or the need_supplicant attribute should be dropped as it isn't very
> > useful. This would maybe be considered an ABI change however.)
>
> The reasoning for this attribute should be explained by commit:
> 7269cba53d90 ("tee: optee: Fix supplicant based device enumeration").
> In summary it's due to a weird dependency for devices we have with the
> user-space daemon: tee-supplicant.
From reading that once I don't understand it. (But no need to explain
:-)
Still the file should better be added before device_add() is called.
> > - Why does optee_probe() in drivers/tee/optee/smc_abi.c unregister all
> > optee devices in its error path (optee_unregister_devices())?
>
> This is mostly to take care of if any device got registered before the
> failure occured. Let me know if you have a better way to address that.
Without understanding the tee stuff, I'd say: Don't bother and only undo
the things that probe did before the failure.
Best regards
Uwe
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