Re: [PATCH V4 0/5] mlx5 ConnectX control misc driver

[Christoph Hellwig <hch@infradead.org>]

Chmining in late after a vacation last week, but I really do not
understand the discussion this cause.

Complex devices need diagnostics, and mlx5ctl and the (free software)
userspace tool provide that.  Given how it is a complex multi-subsystem
driver that exports at least RDMA, ethernet, nvme and virtio_blk
interfaces this functionality by definition can't fit into a single
subsystem.

So with my nvme co-maintainer hat on:

Acked-by: Christoph Hellwig <hch@lst.de>

to th concept (which is not a full code review!).

With my busy kernel contributor head on I have to voice my
dissatisfaction with the subsystem maintainer overreach that's causing
the troubles here.  I think all maintainers can and should voice the
opinions, be those technical or political, but trying to block a useful
feature without lots of precedence because it is vaguely related to the
subsystem is not helpful.  Note that this is absolutely not intended to
shut the discussion down - if we can find valid arguments why some of
this functionality should also be reported through a netdev API we
should continue that.  E.g. just because we have SCSI, NVMe or product
specific passthrough interface we still try to provide useful common
interface generically.