wifi: mwl8k: inject DSSS Parameter Set element into beacons if missing

Some Marvell AP firmware used with mwl8k misbehaves when beacon frames
do not contain a WLAN_EID_DS_PARAMS element with the current channel.
It was reported on OpenWrt Github issues [0].

When hostapd/mac80211 omits DSSS Parameter Set from the beacon (which is
valid on some bands), the firmware stops transmitting sane frames and RX
status starts reporting bogus channel information. This makes AP mode
unusable.

Newer Marvell drivers (mwlwifi [1]) hard-code DSSS Parameter Set into
AP beacons for all chips, which suggests this is a firmware requirement
rather than a mwl8k-specific quirk.

Mirror that behaviour in mwl8k: when setting the beacon, check if
WLAN_EID_DS_PARAMS is present, and if not, extend the beacon and inject
a DSSS Parameter Set element, using the current channel from
hw->conf.chandef.chan.

Tested on Linksys EA4500 (88W8366).

[0] https://github.com/openwrt/openwrt/issues/19088
[1] https://github.com/kaloz/mwlwifi/blob/db97edf20fadea2617805006f5230665fadc6a8c/hif/fwcmd.c#L675

Fixes: b64fe619e371 ("mwl8k: basic AP interface support")
Tested-by: Antony Kolitsos <zeusomighty@hotmail.com>
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Link: https://patch.msgid.link/20251111100733.2825970-3-paweldembicki@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

0 files changed, 0 insertions, 0 deletions