Consider the following step-by step: 1. A STA authenticates and associates with the AP and exchanges traffic. 2. The STA reports to the AP that it is going to PS state. 3. Some time later the STA device goes to the stand-by mode (not only its wi-fi card, but the device itself) and drops the association state without sending a disassociation frame. 4. The STA device wakes up and begins authentication with an Auth frame as it hasn't been authenticated/associated previously. At the step 4 the AP "remembers" the STA and considers it is still in the PS state, so the AP buffers frames, which it has to send to the STA. But the STA isn't actually in the PS state and so it neither checks TIM bits nor reports to the AP that it isn't power saving. Because of that authentication/[re]association fails. To fix authentication/[re]association stage of this issue, Auth, Assoc Resp and Reassoc Resp frames are transmitted disregarding of STA's power saving state. N.B. This patch doesn't fix further data frame exchange after authentication/[re]association. A patch in hostapd is required to fix that. Signed-off-by: Igor Perminov <igor.perminov@xxxxxxxx> --- net/mac80211/tx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 10a1099..4d981e7 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -367,7 +367,10 @@ ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx) struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; u32 staflags; - if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control))) + if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control) + || ieee80211_is_auth(hdr->frame_control) + || ieee80211_is_assoc_resp(hdr->frame_control) + || ieee80211_is_reassoc_resp(hdr->frame_control))) return TX_CONTINUE; staflags = get_sta_flags(sta); -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
