Re: [PATCH wireless v2] nl80211/cfg80211: add nla_policy for S1G band

From: Johannes Berg
Date: Sat Jan 20 2024 - 15:27:50 EST


On Fri, 2024-01-19 at 15:47 -0800, Jeff Johnson wrote:
> > --- a/net/wireless/nl80211.c
> > +++ b/net/wireless/nl80211.c
> > @@ -911,6 +911,7 @@ nl80211_match_band_rssi_policy[NUM_NL80211_BANDS] = {
> > [NL80211_BAND_5GHZ] = { .type = NLA_S32 },
> > [NL80211_BAND_6GHZ] = { .type = NLA_S32 },
> > [NL80211_BAND_60GHZ] = { .type = NLA_S32 },
> > + [NL80211_BAND_S1GHZ] = { .type = NLA_S32 },
> > [NL80211_BAND_LC] = { .type = NLA_S32 },
> > };
> >
> something is really suspicious since the NL80211_BAND_* enums are
> *value* enums, not attribute ID enums, and hence they should never be
> used in an nla_policy.

Yeah, that's what it looks like first, but then they do get used
anyway...

> what is actually using these as attribute IDs, noting that
> NL80211_BAND_2GHZ == 0 and hence cannot be used as an attribute ID

Ohh. Good catch!

> seems the logic that introduced this policy needs to be revisited.
>

Let's just remove it?

commit 1e1b11b6a1111cd9e8af1fd6ccda270a9fa3eacf
Author: vamsi krishna <vamsin@xxxxxxxxxxxxxx>
Date: Fri Feb 1 18:34:51 2019 +0530

nl80211/cfg80211: Specify band specific min RSSI thresholds with sched scan


As far as I can tell nothing is using that in the first place ...
Certainly not in the kernel, nor wpa_s, nor anything else I could find
really ...

We can't completely revert it since we need the attribute number to stay
allocated, but that's all we cannot remove.

johannes