[PATCH wireless-next] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags

[PATCH wireless-next] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

These were used by S1G for older chandef representation, but
are no longer needed. Clean them up, even if we can't drop
them from the userspace API entirely.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/cfg80211.h | 16 +---------------
 net/wireless/nl80211.c | 15 ---------------
 2 files changed, 1 insertion(+), 30 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 1c041ce7a03b..781624f5913a 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -101,16 +101,6 @@ struct wiphy;
  * @IEEE80211_CHAN_NO_10MHZ: 10 MHz bandwidth is not permitted
  *	on this channel.
  * @IEEE80211_CHAN_NO_HE: HE operation is not permitted on this channel.
- * @IEEE80211_CHAN_1MHZ: 1 MHz bandwidth is permitted
- *	on this channel.
- * @IEEE80211_CHAN_2MHZ: 2 MHz bandwidth is permitted
- *	on this channel.
- * @IEEE80211_CHAN_4MHZ: 4 MHz bandwidth is permitted
- *	on this channel.
- * @IEEE80211_CHAN_8MHZ: 8 MHz bandwidth is permitted
- *	on this channel.
- * @IEEE80211_CHAN_16MHZ: 16 MHz bandwidth is permitted
- *	on this channel.
  * @IEEE80211_CHAN_NO_320MHZ: If the driver supports 320 MHz on the band,
  *	this flag indicates that a 320 MHz channel cannot use this
  *	channel as the control or any of the secondary channels.
@@ -152,11 +142,7 @@ enum ieee80211_channel_flags {
 	IEEE80211_CHAN_NO_20MHZ			= BIT(11),
 	IEEE80211_CHAN_NO_10MHZ			= BIT(12),
 	IEEE80211_CHAN_NO_HE			= BIT(13),
-	IEEE80211_CHAN_1MHZ			= BIT(14),
-	IEEE80211_CHAN_2MHZ			= BIT(15),
-	IEEE80211_CHAN_4MHZ			= BIT(16),
-	IEEE80211_CHAN_8MHZ			= BIT(17),
-	IEEE80211_CHAN_16MHZ			= BIT(18),
+	/* can use free bits here */
 	IEEE80211_CHAN_NO_320MHZ		= BIT(19),
 	IEEE80211_CHAN_NO_EHT			= BIT(20),
 	IEEE80211_CHAN_DFS_CONCURRENT		= BIT(21),
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index de34a1d14073..346dfd2bd987 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1280,21 +1280,6 @@ static int nl80211_msg_put_channel(struct sk_buff *msg, struct wiphy *wiphy,
 		if ((chan->flags & IEEE80211_CHAN_NO_HE) &&
 		    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_NO_HE))
 			goto nla_put_failure;
-		if ((chan->flags & IEEE80211_CHAN_1MHZ) &&
-		    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_1MHZ))
-			goto nla_put_failure;
-		if ((chan->flags & IEEE80211_CHAN_2MHZ) &&
-		    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_2MHZ))
-			goto nla_put_failure;
-		if ((chan->flags & IEEE80211_CHAN_4MHZ) &&
-		    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_4MHZ))
-			goto nla_put_failure;
-		if ((chan->flags & IEEE80211_CHAN_8MHZ) &&
-		    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_8MHZ))
-			goto nla_put_failure;
-		if ((chan->flags & IEEE80211_CHAN_16MHZ) &&
-		    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_16MHZ))
-			goto nla_put_failure;
 		if ((chan->flags & IEEE80211_CHAN_NO_320MHZ) &&
 		    nla_put_flag(msg, NL80211_FREQUENCY_ATTR_NO_320MHZ))
 			goto nla_put_failure;
-- 
2.51.0

Re: [PATCH wireless-next] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags

[Lachlan Hodges]

On Fri, Sep 19, 2025 at 12:23:25PM +0200, Johannes Berg wrote:
> These were used by S1G for older chandef representation, but
> are no longer needed. Clean them up, even if we can't drop
> them from the userspace API entirely.

Thanks for removing these, probably should have done it as part
of my patchset.. Looks much better now.

lachlan

[syzbot ci] Re: wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags

[syzbot ci]

syzbot ci has tested the following series

[v1] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags
https://lore.kernel.org/all/20250919122325.f0abcf092b9b.I04478fde87a79c7909f1cc4249430deaf71e8bd0@changeid
* [PATCH wireless-next] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags

and found the following issue:
kernel build error

Full report is available here:
https://ci.syzbot.org/series/56aae9dc-2280-4bc7-9761-a0d119923350

***

kernel build error

tree:      torvalds
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base:      f83ec76bf285bea5727f478a68b894f5543ca76e
arch:      amd64
compiler:  Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config:    https://ci.syzbot.org/builds/9c1d861d-4d4d-4c90-a946-8769043ca3e6/config

net/wireless/util.c:118:20: error: use of undeclared identifier 'IEEE80211_CHAN_1MHZ'
net/wireless/util.c:120:25: error: use of undeclared identifier 'IEEE80211_CHAN_2MHZ'
net/wireless/util.c:122:25: error: use of undeclared identifier 'IEEE80211_CHAN_4MHZ'
net/wireless/util.c:124:25: error: use of undeclared identifier 'IEEE80211_CHAN_8MHZ'
net/wireless/util.c:126:25: error: use of undeclared identifier 'IEEE80211_CHAN_16MHZ'
net/wireless/reg.c:1734:18: error: use of undeclared identifier 'IEEE80211_CHAN_1MHZ'
net/wireless/reg.c:1737:18: error: use of undeclared identifier 'IEEE80211_CHAN_2MHZ'
net/wireless/reg.c:1740:18: error: use of undeclared identifier 'IEEE80211_CHAN_4MHZ'
net/wireless/reg.c:1743:18: error: use of undeclared identifier 'IEEE80211_CHAN_8MHZ'
net/wireless/reg.c:1746:18: error: use of undeclared identifier 'IEEE80211_CHAN_16MHZ'

***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

Re: [syzbot ci] Re: wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags

[Johannes Berg]

On Fri, 2025-09-19 at 22:32 -0700, syzbot ci wrote:
> syzbot ci has tested the following series
> 
> [v1] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags
> https://lore.kernel.org/all/20250919122325.f0abcf092b9b.I04478fde87a79c7909f1cc4249430deaf71e8bd0@changeid
> * [PATCH wireless-next] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags
> 
> and found the following issue:
> kernel build error

Hmm. I don't know if this is really useful? The 0-day bot does similar
build tests, probably more comprehensively, and

> tree:      torvalds
> URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
> base:      f83ec76bf285bea5727f478a68b894f5543ca76e

unlike syzbot, I'm pretty sure it would've known not to attempt applying
the patches to Linus's tree when they were destined to wireless-next.


IMHO there's enough noise already, this only adds to the noise, not to
the signal.

johannes

Re: [syzbot ci] Re: wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags

[Aleksandr Nogikh]

On Mon, Sep 22, 2025 at 9:46 AM Johannes Berg <johannes@sipsolutions.net> wrote:
>
> On Fri, 2025-09-19 at 22:32 -0700, syzbot ci wrote:
> > syzbot ci has tested the following series
> >
> > [v1] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags
> > https://lore.kernel.org/all/20250919122325.f0abcf092b9b.I04478fde87a79c7909f1cc4249430deaf71e8bd0@changeid
> > * [PATCH wireless-next] wifi: cfg80211: remove IEEE80211_CHAN_{1,2,4,8,16}MHZ flags
> >
> > and found the following issue:
> > kernel build error
>
> Hmm. I don't know if this is really useful? The 0-day bot does similar
> build tests, probably more comprehensively, and
>
> > tree:      torvalds
> > URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
> > base:      f83ec76bf285bea5727f478a68b894f5543ca76e
>
> unlike syzbot, I'm pretty sure it would've known not to attempt applying
> the patches to Linus's tree when they were destined to wireless-next.
>
>
> IMHO there's enough noise already, this only adds to the noise, not to
> the signal.

I'll drop reporting build errors from syzbot ci so that only fuzzer
bugs are reported, thanks for the feedback.

-- 
Aleksandr

>
> johannes
>
> --