On Wed, Jan 23, 2019 at 11:21:25PM -0800, Life is hard, and then you die wrote:

Since the two changes (the change here + the new driver) seem to be
best submitted through different trees, I'm trying to figure out how
best to handle this. I suppose I could temporarily change the driver
Kconfig to not trigger the conflict, and then once the change here has
been upstreamed (not sure at what point exactly that would be
considered the case, e.g. if in linux-next is sufficient, or has to
wait for Linus' merge, or something else) submit another change to
change the driver's Kconfig to the desired one.

If a series touches multiple subsystems and its patches are interdependent,
the pull requests sent to Linus would have to be merged in a specific order.

In practice that's too cumbersome, so either the series is split in multiple
parts and merged across multiple releases (which obviously can take a long
time) or, if the change to other subsystems is smallish (as is the case
here), the entire series is merged through a single subsystem tree and
those patches touching other subsystems need to have an Acked-by or
Reviewed-by tag from a maintainer of those other subsystems.

If a case can be made that the change to the other subsystem (e.g. DRM) is
actually a bug fix, then that change can go in immediately and will appear
in one of Linus' next -rc releases.  The rest of the series can then go
through the appropriate subsystem (e.g. input) and will land in Linus' tree
in the next merge window.

Either way, the correct patch order is preserved and it's guaranteed that
the build is not broken for someone ending up on an in-between commit while
bisecting.

HTH,

Lukas