Re: [PATCH 3/3] drivers: always enable the null net driver [RFC]

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Jan 22, 2026 at 02:47:47PM +0100, David Marchand wrote:
> On Thu, 22 Jan 2026 at 14:32, Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > On Thu, Jan 22, 2026 at 02:13:06PM +0100, Morten Brørup wrote:
> > > > From: Bruce Richardson [mailto:bruce.richardson@intel.com]
> > > > Sent: Thursday, 22 January 2026 13.24
> > > >
> > > > Having the net_null driver always available can be convenient and
> > > > allows
> > > > use by unit tests, so add this trivial driver to the always-enable
> > > > list.
> > > >
> > > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > > >
> > > > ---
> > > > I'm not sure if we want this to be always enabled or not, so sending
> > > > this as an RFC. I can see definite advantages to doing so, but I also
> > > > dislike having too many components on the always-enable list.
> > > >
> > > > Since I'm ambivilent myself, including this patch so the community can
> > > > decide.
> > >
> > > I don't think real applications use this.
> > > If they do, they can include it manually.
> > >
> > > My main objection is:
> > > We are setting the wrong precedence if we make stuff like this mandatory for convenience.
> > >
> > > But I agree with the reason you are suggesting it.
> > >
> > > Is there some other way it can be enabled for unit tests?
> > > Maybe the null driver can depend on the unit tests being built?
> > >
> > > I don't mind that the driver is being built.
> > > I just don't want it included by default when statically linking a monolithic application.
> 
> Same, I don't want a driver with almost no maintenance on it (even if
> it is trivial code) to be linked in a final application.
> (it would be a pity to get a CVE because of net/null ;-))
> 
> 
> > >
> > > I'm flexible on this RFC, so it's a very soft NAK from me.
> > > If it can be disabled at build time, I'm OK with it. (But still concerned about setting the wrong precedence.)
> > >
> > Yes, I agree.
> >
> > Why I'm proposing this is because, in order to give me faster rebuilds and
> > because of the hardware I have available to me, I generally set up my
> > builds with "-Denable_drivers=net/intel/*", since that really speeds up my
> > dev-build-test cycle. In doing so, though, I do miss out on having some
> > unit tests available when I run the fast-test suite, which is why I
> > suggested this addition in case there are others who limit the builds to
> > just the hardware they are using.
> 
> Unit tests are mainly run by the CI or DPDK developers, so how about
> putting this addition in the always enabled list under the
> developer_mode check?
> 

Yep could work. Possibly also taking a modified version of Morten's
suggestion about warning about skipped tests, what about just emitting a
warning from meson if we are in developer mode and we haven't the net-null
driver enabled?

/Bruce