From a711bf00b8b3c6d879cb5d95bbe921366228b318 Mon Sep 17 00:00:00 2001 From: Masi Osmani Date: Thu, 12 Mar 2026 11:37:58 +0100 Subject: [PATCH] wifi: carl9170: mac80211: document spatial multiplexing power save handler Replace the bare TODO comment in the SMPS configuration handler with documentation explaining why the driver accepts but does not act on SMPS mode changes. The AR9170 advertises SM_PS disabled (both chains always active) in its HT capabilities. While mac80211 may still send SMPS configuration requests, implementing static or dynamic SMPS would require firmware support for per-chain enable/disable that the AR9170 firmware (v1.9.9) does not provide. Signed-off-by: Masi Osmani Acked-by: Christian Lamparter Link: https://patch.msgid.link/AM7PPF5613FA0B6B76223A73FFC756A19A99444A@AM7PPF5613FA0B6.EURP251.PROD.OUTLOOK.COM Signed-off-by: Jeff Johnson --- drivers/net/wireless/ath/carl9170/main.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/carl9170/main.c b/drivers/net/wireless/ath/carl9170/main.c index af632418fa06..61c7a1288743 100644 --- a/drivers/net/wireless/ath/carl9170/main.c +++ b/drivers/net/wireless/ath/carl9170/main.c @@ -908,7 +908,13 @@ static int carl9170_op_config(struct ieee80211_hw *hw, int radio_idx, u32 change } if (changed & IEEE80211_CONF_CHANGE_SMPS) { - /* TODO */ + /* + * We advertise SM_PS disabled (all chains active). + * mac80211 may still request mode changes, which we + * accept but only support OFF (both chains active). + * Static/dynamic SMPS would require firmware support + * for chain control that the AR9170 does not provide. + */ err = 0; }