Re: [PATCH v5] driver core: enforce device_lock for driver_match_device()

[Cristian Marussi <cristian.marussi@arm.com>]

On Wed, Jan 14, 2026 at 12:28:43AM +0800, Gui-Dong Han wrote:
> Currently, driver_match_device() is called from three sites. One site
> (__device_attach_driver) holds device_lock(dev), but the other two
> (bind_store and __driver_attach) do not. This inconsistency means that
> bus match() callbacks are not guaranteed to be called with the lock
> held.
> 
> Fix this by introducing driver_match_device_locked(), which guarantees
> holding the device lock using a scoped guard. Replace the unlocked calls
> in bind_store() and __driver_attach() with this new helper. Also add a
> lock assertion to driver_match_device() to enforce this guarantee.

Hi,

it has been reported by Gatien (in CC) that this break the SCMI OPTEE
transport.

Moreover I still have to verify, BUT I think this also breaks SCMI
Virtio transport since both call platform_driver_register() during their
probe, since a few years ago the SCMI transports have been reworked to be
standalone full-fledged drivers.

I'll have a look in the next days if we can cope with this.

Thanks,
Cristian