On Tue, Mar 20, 2012 at 3:07 PM, Mohammed Shafi
[off-list ref] wrote:

Hi Sujith/Justin,

On Tue, Mar 20, 2012 at 1:59 PM, Sujith Manoharan
[off-list ref] wrote:

quoted

Justin P. Mattock wrote:

quoted

yeah this works:

eading symbols from
/home/kernel/linux-next/drivers/net/wireless/ath/ath9k/ath9k.o...done.
(gdb) l *(ath_tx_start+0x284)
0xcad4 is in ath_tx_start (drivers/net/wireless/ath/ath9k/xmit.c:1878).
1873                  ieee80211_is_data_qos(hdr->frame_control)) {
1874                  tidno = ieee80211_get_qos_ctl(hdr)[0] &
1875                          IEEE80211_QOS_CTL_TID_MASK;
1876                  tid = ATH_AN_2_TID(txctl->an, tidno);
1877
1878                  WARN_ON(tid->ac->txq != txctl->txq);
1879          }
1880
1881          if ((tx_info->flags & IEEE80211_TX_CTL_AMPDU) && tid) {
1882                  /*
(gdb)

Can you try this patch ?

just found out that 'ht_supported' may not  be set, if assoc response
does not has ht_cap IE (or) if we could not parse it (why), then the
driver won't initialize those tid related structures ath_tx_node_init,
while we later access them in ath_tx_start. so this should fix the
issue.

now i was able to quite easily recreate this issue in wireless testing
even without suspend resume and with the patch the issue seems to get
fixed.
i was using 2ghz channel 6 and TKIP (no HT!).

quoted

From: Sujith Manoharan <redacted>
Date: Tue, 20 Mar 2012 13:51:26 +0530
Subject: [PATCH] ath9k: Use HW HT capabilites properly

The commit "ath9k: Remove aggregation flags" changed how
nodes were being initialized. Use the HW HT cap bits
to initialize/de-initialize nodes, else we would be
accessing an uninitialized entry during a suspend/resume cycle,
resulting in a panic.

Reported-by: Justin P. Mattock <redacted>
Signed-off-by: Sujith Manoharan <redacted>
---
 drivers/net/wireless/ath/ath9k/main.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 3879485..215eb25 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c

@@ -640,7 +640,7 @@ static void ath_node_attach(struct ath_softc *sc, struct ieee80211_sta *sta,

       an->sta = sta;
       an->vif = vif;

-       if (sta->ht_cap.ht_supported) {
+       if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_HT) {
               ath_tx_node_init(sc, an);
               an->maxampdu = 1 << (IEEE80211_HT_MAX_AMPDU_FACTOR +
                                    sta->ht_cap.ampdu_factor);

@@ -659,7 +659,7 @@ static void ath_node_detach(struct ath_softc *sc, struct ieee80211_sta *sta)

       an->sta = NULL;
 #endif

-       if (sta->ht_cap.ht_supported)
+       if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_HT)
               ath_tx_node_cleanup(sc, an);
 }

--
1.7.9.4

--
thanks,
shafi

-- 
thanks,
shafi