Re: [PATCH] firmware: arm_scmi: Fix virtio transport Kconfig dependency

[Arnd Bergmann <arnd@kernel.org>]

On Mon, Aug 16, 2021 at 4:16 PM Cristian Marussi
<cristian.marussi@arm.com> wrote:
>
> ARM_SCMI_TRANSPORT_VIRTIO is a 'bool' Kconfig used to include support for
> the SCMI virtio transport inside the core SCMI stack; a bare transport
> dependency attached here to this option, though, cannot be properly
> propagated to the parent ARM_SCMI_PROTOCOL option and, as a result, it is
> currently possible to configure a Kernel where SCMI core is builtin
> and includes support for virtio while VirtIO core is =m.
> This allowed combination breaks linking:
>
>         ARM_SCMI_PROTOCOL=y
>         ARM_SCMI_TRANSPORT_VIRTIO=y
>         VIRTIO=m
>
> Bind the dependency in ARM_SCMI_TRANSPORT_VIRTIO to the chosen kind of
> compilation of ARM_SCMI_PROTOCOL.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Suggested-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>

The description looks good

Acked-by: Arnd Bergmann <arnd@arndb.de>

> @@ -68,7 +68,7 @@ config ARM_SCMI_TRANSPORT_SMC
>
>  config ARM_SCMI_TRANSPORT_VIRTIO
>         bool "SCMI transport based on VirtIO"
> -       depends on VIRTIO
> +       depends on VIRTIO=y || VIRTIO=ARM_SCMI_PROTOCOL
>         select ARM_SCMI_HAVE_TRANSPORT
>         select ARM_SCMI_HAVE_MSG

Looking at this again, I noticed that this still needs the explicit
'depends on VIRTIO' line you removed, otherwise the prompt
pops up when both VIRTIO and ARM_SCMI_PROTOCOL
are disabled.

       Arnd