DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C5D1920875
Date:   Fri, 5 Oct 2018 10:37:49 +0200
From:   Stanislaw Gruszka <sgruszka@redhat.com>
To:     Manikanta Pubbisetty <mpubbise@codeaurora.org>
Cc:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org
Subject: crash in ieee80211_wake_txqs
Message-ID: <20181005083748.GD1931@redhat.com>
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Hi

I have crash in ieee80211_wake_txqs:
https://imgur.com/a/VIrU9yK
when starting mt76x0u driver. Not sure if this is beacuse the driver
do not initalize sta->txq properly, but reverting the

commit 21a5d4c3a45ca608477a083096cfbce76e449a0c
Author: Manikanta Pubbisetty <mpubbise@codeaurora.org>
Date:   Wed Jul 11 00:12:53 2018 +0530

    mac80211: add stop/start logic for software TXQs

make crash gone.

gdb pointed at 'if (ac != txq->ac)' line in the code:

               for (i = 0; i < ARRAY_SIZE(sta->sta.txq); i++) {
                       struct ieee80211_txq *txq = sta->sta.txq[i];

                       txqi = to_txq_info(txq);

                       if (ac != txq->ac)
                               continue;

Looks txq is NULL and referencing txq->ac crashes.

Thanks
Stanislaw