Re: [PATCH 4.20 018/352] ath9k: dynack: use authentication messages for late ack

From: Koen Vandeputte
Date: Mon Feb 11 2019 - 10:48:37 EST

On 11.02.19 15:14, Greg Kroah-Hartman wrote:
4.20-stable review patch. If anyone has any objections, please let me know.


[ Upstream commit 3831a2a0010c72e3956020cbf1057a1701a2e469 ]

In order to properly support dynack in ad-hoc mode running
wpa_supplicant, take into account authentication frames for
'late ack' detection. This patch has been tested on devices
mounted on offshore high-voltage stations connected through
~24Km link

Reported-by: Koen Vandeputte <koen.vandeputte@xxxxxxxxxxxx>
Tested-by: Koen Vandeputte <koen.vandeputte@xxxxxxxxxxxx>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/net/wireless/ath/ath9k/dynack.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c
index 7334c9b09e82..cc0dc966c512 100644
--- a/drivers/net/wireless/ath/ath9k/dynack.c
+++ b/drivers/net/wireless/ath/ath9k/dynack.c
@@ -187,7 +187,8 @@ void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb,
/* late ACK */
if (ts->ts_status & ATH9K_TXERR_XRETRY) {
if (ieee80211_is_assoc_req(hdr->frame_control) ||
- ieee80211_is_assoc_resp(hdr->frame_control)) {
+ ieee80211_is_assoc_resp(hdr->frame_control) ||
+ ieee80211_is_auth(hdr->frame_control)) {
ath_dbg(common, DYNACK, "late ack\n");
ath9k_hw_setslottime(ah, (LATEACK_TO - 3) / 2);
ath9k_hw_set_ack_timeout(ah, LATEACK_TO);

Dear Greg,

No idea if this is the proper location to report this or if I should inform stable@xxxxxx , but:

This backport alone is useless without backporting following 2 commits below also, unless the 2 wifi devices using dynack start off at very close distance.

Their commits messages indicate them as improvements, but they should be considered as fixes.

It's safe to add them to all stables involved (4.20, 4.19, 4.14, 4.9)