Re: [PATCH wireless-next] wifi: nl80211: add support to configure 6 GHz non-HT duplicate transmission

On 8/5/2026 2:56 PM, Manish Dharanenthiran wrote:
> As per IEEE Std 802.11-2024, subclause 26.17.2.2, a 6 GHz AP can transmit
> a Beacon frame using a non-HT duplicate PPDU, so that stations scanning
> only PSC channels can discover it. Currently, there is no mechanism
> to request the driver to transmit non-HT duplicate Beacon frames.
>
> In [1], changes were made to parse the Beacon from user-space to set
> the non-HT duplicate flag in the kernel. However, it was suggested that
> non-HT transmission be part of the Beacon TX rate settings. Hence, add
> NL80211_TXRATE_6GHZ_NON_HT_DUP as a flag attribute under
> NL80211_ATTR_TX_RATES to let user-space request the driver to transmit
> non-HT duplicate Beacons.
>
> Also add validation to reject the Beacon if non-HT duplicate Beacon
> transmission is enabled when legacy rates are not configured.
>
> [1]  https://lore.kernel.org/all/[email protected]/
>
> Signed-off-by: Manish Dharanenthiran <[email protected]>
> ---
> Note: Users(ath11k&ath12k) of this new NL attribute will be posted later
> once this gets approved.
> ---
>   include/net/cfg80211.h       |  1 +
>   include/uapi/linux/nl80211.h |  4 ++++
>   net/wireless/nl80211.c       | 13 +++++++++++++
>   3 files changed, 18 insertions(+)
>
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index 97c16d4ff127..6bc490108303 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -901,6 +901,7 @@ struct cfg80211_bitrate_mask {
>   		enum nl80211_eht_gi eht_gi;
>   		enum nl80211_he_ltf he_ltf;
>   		enum nl80211_eht_ltf eht_ltf;
> +		bool nonht_dup_6ghz;
>   	} control[NUM_NL80211_BANDS];
>   };
>   
> diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
> index 020387d76412..d8fefefc11a9 100644
> --- a/include/uapi/linux/nl80211.h
> +++ b/include/uapi/linux/nl80211.h
> @@ -5900,6 +5900,9 @@ enum nl80211_key_attributes {
>    *	see &struct nl80211_txrate_eht
>    * @NL80211_TXRATE_EHT_GI: configure EHT GI, (u8, see &enum nl80211_eht_gi)
>    * @NL80211_TXRATE_EHT_LTF: configure EHT LTF, (u8, see &enum nl80211_eht_ltf)
> + * @NL80211_TXRATE_6GHZ_NON_HT_DUP: configure 6 GHz non-HT duplicate Beacon
> + *	transmission. This flag is applicable only in Beacon TX rate setting
> + *	and must be accompanied by a non-HT (legacy) Beacon rate.
>    * @__NL80211_TXRATE_AFTER_LAST: internal
>    * @NL80211_TXRATE_MAX: highest TX rate attribute
>    */
> @@ -5915,6 +5918,7 @@ enum nl80211_tx_rate_attributes {
>   	NL80211_TXRATE_EHT,
>   	NL80211_TXRATE_EHT_GI,
>   	NL80211_TXRATE_EHT_LTF,
> +	NL80211_TXRATE_6GHZ_NON_HT_DUP,
>   
>   	/* keep last */
>   	__NL80211_TXRATE_AFTER_LAST,
> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
> index 44f2bad08670..cb4752fc38a0 100644
> --- a/net/wireless/nl80211.c
> +++ b/net/wireless/nl80211.c
> @@ -569,6 +569,7 @@ static const struct nla_policy nl80211_txattr_policy[NL80211_TXRATE_MAX + 1] = {
>   	[NL80211_TXRATE_EHT_LTF] = NLA_POLICY_RANGE(NLA_U8,
>   						   NL80211_RATE_INFO_EHT_1XLTF,
>   						   NL80211_RATE_INFO_EHT_8XLTF),
> +	[NL80211_TXRATE_6GHZ_NON_HT_DUP] = { .type = NLA_FLAG },
>   
>   };
>   
> @@ -6303,6 +6304,14 @@ static int nl80211_parse_tx_bitrate_mask(struct genl_info *info,
>   			mask->control[band].eht_ltf =
>   				nla_get_u8(tb[NL80211_TXRATE_EHT_LTF]);
>   
> +		if (tb[NL80211_TXRATE_6GHZ_NON_HT_DUP]) {
> +			if (band != NL80211_BAND_6GHZ ||
> +			    (wdev->iftype != NL80211_IFTYPE_AP &&
> +			     wdev->iftype != NL80211_IFTYPE_P2P_GO))
> +				return -EINVAL;
> +			mask->control[band].nonht_dup_6ghz = true;
> +		}
> +
>   		if (mask->control[band].legacy == 0) {
>   			/* don't allow empty legacy rates if HT, VHT, HE or EHT
>   			 * are not even supported.
> @@ -6344,6 +6353,7 @@ static int validate_beacon_tx_rate(struct cfg80211_registered_device *rdev,
>   {
>   	u32 count_ht, count_vht, count_he, count_eht, i;
>   	u32 rate = beacon_rate->control[band].legacy;
> +	bool nonht_dup = beacon_rate->control[band].nonht_dup_6ghz;
>   
>   	/* Allow only one rate */
>   	if (hweight32(rate) > 1)
> @@ -6405,6 +6415,9 @@ static int validate_beacon_tx_rate(struct cfg80211_registered_device *rdev,
>   	    (!rate && !count_ht && !count_vht && !count_he && !count_eht))
>   		return -EINVAL;
>   
> +	if (nonht_dup && !rate)
> +		return -EINVAL;


Since the changes introduce NL80211_TXRATE_6GHZ_NON_HT_DUP as a separate 
configuration parameter,
should cfg80211 verify consistency with the Beacon template's HE 
operation duplicate beacon subfield?


> +
>   	if (rate &&
>   	    !wiphy_ext_feature_isset(&rdev->wiphy,
>   				     NL80211_EXT_FEATURE_BEACON_RATE_LEGACY))
>
> ---
> base-commit: 6c5fc504d0d6934132637aa3db4b9b58148eaa78
> change-id: 20260805-dup-beacon-0d074e15ecf7
>
>