Re: [PATCH v2] wifi: mwl8k: inject DSSS Parameter Set element into beacons if missing

From: Johannes Berg
Date: Tue Nov 11 2025 - 02:38:43 EST


>
> ---
> V2:
> - added "wifi:" prefix to commit title
> - renamed "DS Params" -> "DSSS Parameter Set"
> - Insert WLAN_EID_DS_PARAMS after WLAN_EID_SSID, WLAN_EID_SUPP_RATES
> and WLAN_EID_EXT_SUPP_RATES

FWIW, per spec it should be between them:

- SSID
- Supported Rates
- DSSS Parameter Set
- TIM
- Country
- ...
- Extended Supported Rates

so actually Extended Supported Rates is also in the _tail_ part of the
cfg80211 API.


> ---
> drivers/net/wireless/marvell/mwl8k.c | 71 ++++++++++++++++++++++++++--
> 1 file changed, 66 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/wireless/marvell/mwl8k.c b/drivers/net/wireless/marvell/mwl8k.c
> index 891e125ad30b..914a566d700a 100644
> --- a/drivers/net/wireless/marvell/mwl8k.c
> +++ b/drivers/net/wireless/marvell/mwl8k.c
> @@ -2966,6 +2966,52 @@ mwl8k_cmd_rf_antenna(struct ieee80211_hw *hw, int antenna, int mask)
> /*
> * CMD_SET_BEACON.
> */
> +
> +static bool mwl8k_beacon_has_ds_params(const u8 *buf, int len)
> +{
> + const struct ieee80211_mgmt *mgmt = (const void *)buf;
> + int ies_len;
> +
> + if (len <= offsetof(struct ieee80211_mgmt, u.beacon.variable))
> + return false;
> +
> + ies_len = len - offsetof(struct ieee80211_mgmt, u.beacon.variable);
> +
> + return cfg80211_find_ie(WLAN_EID_DS_PARAMS, mgmt->u.beacon.variable,
> + ies_len) != NULL;
> +}
> +
> +static void mwl8k_beacon_copy_inject_ds_params(struct ieee80211_hw *hw,
> + u8 *buf_dst, const u8 *buf_src,
> + int src_len)
> +{
> + const struct ieee80211_mgmt *mgmt = (const void *)buf_src;
> + static const u8 before_ds_params[] = {
> + WLAN_EID_SSID,
> + WLAN_EID_SUPP_RATES,
> + WLAN_EID_EXT_SUPP_RATES,
> + };

nit: seems on tab would be nicer?

> - cmd = kzalloc(sizeof(*cmd) + len, GFP_KERNEL);
> + if (!ds_params_present)
> + /*
> + * mwl8k firmware requires a DS Params IE with the current
> + * channel in AP beacons. If mac80211/hostapd does not
> + * include it, inject one here. IE ID + length + channel
> + * number = 3 bytes.
> + */
> + final_len += 3;
> +

another nit: I'd probably add braces

johannes