On Thu, Oct 27, 2022 at 06:00:04PM +0200, Michael Walle wrote:
> > - change the MODULE_ALIAS() of all tagging protocol driver modules from
> > "dsa_tag-<number" to something containing their string name - what you
> > proposed. I don't know why the current MODULE_ALIAS() is formatted the
> > way it is. Maybe Andrew can comment on whether this is feasible.
> > I think there isn't any backwards compatibility concern, since only
> > modules compiled for a certain kernel version are expected to be
> > loaded.
>
> FWIW, you can have multiple aliases if we somehow need to keep the IDs,
> too.
Yeah, that's worth exploring, but it means that we have 2 code paths for
request_module() with different string formats. To me this is slightly
undesirable, we should try to consolidate the mechanisms in the core.
> > - put a translation table between string and MODULE_ALIAS() inside
> > dsa_core.ko, which potentially duplicates code. Maybe if we
> > auto-generate it somehow?
>
> Yeah, I also thought of a table with of name to module alias mapping.
> But then you'd have two places to keep in sync (of not autogenerated).
Well, to be fair, this is not exactly true. As far as I could find
(grep for "ops->name" in net/dsa), there are only 3 instances of reading
the "name" field of struct dsa_device_ops, and none of them are from a
fast path.
I can imagine a table along the lines of:
static const char * const dsa_tag_proto_names[] = {
[DSA_TAG_PROTO_NONE] = "none",
[DSA_TAG_PROTO_BRCM] = "brcm",
....
};
which is then used to directly replace ops->name
(becomes dsa_tag_proto_names[ops->proto]).
Then, we could add a new function "dsa_tag_protocol_name_to_id()" or
something along those lines, and construct the modalias string based on
that.
No duplication necessary, since we would remove dsa_device_ops :: name.
