Bogus dependency for HW_RANDOM_VIRTIO with oldconfig

I'm new here and not sure if I'm contacting the correct people/groups -- please point me in the right direction if not. I don't know if the culprit here is Kconfig, the virtio Kconfig file, the hw_random Kconfig file, or some combination of those.

I believe I have discovered an issue with the order in which make oldconfig asks for virtio-related options, and would appreciate some advice on how to solve it:

HW_RANDOM_VIRTIO=y depends on VIRTIO=y. In my kernel, VIRTIO=y is selected by VIRITO_PCI=y, but when make oldconfig prompts for HW_RANDOM_VIRTIO, VIRTIO_PCI has not been prompted for yet, and so VIRTIO is still set to m.

This means that it's not possible for me to set HW_RANDOM_VIRTIO=y using oldconfig without setting an VIRTIO-selecting option I don't need, but that is prompted for _before_ HW_RANDOM_VIRTIO. One such option that I have identified so far is VOP. It is prompted for before HW_RANDOM_VIRTIO, and so if I set VOP=y it is now possible to set HW_RANDOM_VIRTIO.

When using menuconfig on a config file generated with oldconfig, that does not have HW_RANDOM_VIRTIO enabled, I am able to set HW_RANDOM=y and HW_RANDOM_VIRTIO=y, and after saving I can confirm that no other changes have been made to the configuration file. This tells me that there's no need for a dependency on e.g. VOP, except when using oldconfig.

So, I think there is an ordering issue here, and that oldconfig should not prompt for HW_RANDOM_VIRTIO until after any option that might select VIRTIO=y.

I would be happy to try to submit or test a patch to fix this, but I don't know where to go from here.

OK, you are right.

Actually, the oldconfig restarts when it finds a newly-visible option. For example, when VIRTIO is changed from n to y,
oldconfig restarts the menu and shows a prompt for HW_RANDOM_VIRTIO.

But, this does not happen when VIRTIO is changed from m to y.

Perhaps check_conf() could be fixed, though I have not looked into it yet.

Best Regards
Masahiro Yamada