Re: [PATCH 0/8] greybus: support point-to-point topology
From: Greg Kroah-Hartman
Date: Wed Jan 28 2026 - 01:05:09 EST
On Tue, Jan 27, 2026 at 03:23:44PM -0500, Damien Riégel wrote:
> On Fri Jan 16, 2026 at 10:09 AM EST, Greg Kroah-Hartman wrote:
> [...]
>
> >>
> >> The SVC doesn' really serve a purpose here, as there is no bus to
> >> manage, and adding its support only increase the complexity and the code
> >> size needed on memory-constrained devices.
> >
> > Exactly how much memory does a "single point" SVC driver take, vs.
> > adding new P2P functionality everywhere in the code like you just did?
> > Finding that out would be good first before worrying about adding
> > another type of "bus" here please.
>
> Sorry for not giving numbers in the cover letter. We measured 10kB of
> code size difference (which may be on the higher end of the spectrum)
> and in Zephyr [1] they measured a 2kB difference (which is probably on
> the lower end considering the implementation is pretty barebone).
Please submit your "empty" SVC driver, 10kb seems too big to me, I think
we can slim it down, or at the very least, see what is making it "large"
and potentially work to reduce that.
For Zephyr, I thought it was 1kb in the github comments, but still 2kb
seems reasonable :)
thanks,
greg k-h