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
[off-list ref] wrote:

quoted

On Mon, Dec 15, 2025 at 04:54:11PM +0900, Sumit Garg wrote:

quoted

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.

quoted

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.

quoted

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.

quoted

 - 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.

quoted

 - 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