[PATCH AUTOSEL 4.19 170/177] mac80211: consider QoS Null frames for STA_NULLFUNC_ACKED

Sasha Levin
2019-12-10T21:35:58Z

From: Thomas Pedersen <thomas@adapt-ip.com>

[ Upstream commit 08a5bdde3812993cb8eb7aa9124703df0de28e4b ]

Commit 7b6ddeaf27ec ("mac80211: use QoS NDP for AP probing")
let STAs send QoS Null frames as PS triggers if the AP was
a QoS STA. However, the mac80211 PS stack relies on an
interface flag IEEE80211_STA_NULLFUNC_ACKED for
determining trigger frame ACK, which was not being set for
acked non-QoS Null frames. The effect is an inability to
trigger hardware sleep via IEEE80211_CONF_PS since the QoS
Null frame was seemingly never acked.

This bug only applies to drivers which set both
IEEE80211_HW_REPORTS_TX_ACK_STATUS and
IEEE80211_HW_PS_NULLFUNC_STACK.

Detect the acked QoS Null frame to restore STA power save.

Fixes: 7b6ddeaf27ec ("mac80211: use QoS NDP for AP probing")
Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
Link: https://lore.kernel.org/r/20191119053538.25979-4-thomas@adapt-ip.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/status.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 534a604b75c26..f895c656407b5 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -867,7 +867,8 @@ static void __ieee80211_tx_status(struct ieee80211_hw *hw,
I802_DEBUG_INC(local->dot11FailedCount);
}

- if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
+ if ((ieee80211_is_nullfunc(fc) || ieee80211_is_qos_nullfunc(fc)) &&
+ ieee80211_has_pm(fc) &&
ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
!(info->flags & IEEE80211_TX_CTL_INJECTED) &&
local->ps_sdata && !(local->scanning)) {
--
2.20.1