Message-ID: <31021122-d1c1-181b-0b95-2ef1c1592452@nbd.name>
Date:   Sun, 21 Nov 2021 20:37:54 +0100
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Subject: Re: [BISECTED REGRESSION] Wireless networking kernel crashes
Content-Language: en-US
To:     Aaro Koskinen <aaro.koskinen@iki.fi>,
        Johannes Berg <johannes.berg@intel.com>,
        Ryder Lee <ryder.lee@mediatek.com>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org
References: <20211118132556.GD334428@darkstar.musicnaut.iki.fi>
From:   Felix Fietkau <nbd@nbd.name>
In-Reply-To: <20211118132556.GD334428@darkstar.musicnaut.iki.fi>
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Precedence: bulk

On 2021-11-18 14:25, Aaro Koskinen wrote:
> Hello,
> 
> I have tried to upgrade my wireless AP (Raspberry Pi with rt2x00usb)
> from v5.9 to the current mainline, but now it keeps crashing every hour
> or so, basically making my wireless network unusable.
> 
> I have bisected this to:
> 
> commit 03c3911d2d67a43ad4ffd15b534a5905d6ce5c59
> Author: Ryder Lee <ryder.lee@mediatek.com>
> Date:   Thu Jun 17 18:31:12 2021 +0200
> 
>      mac80211: call ieee80211_tx_h_rate_ctrl() when dequeue
> 
> With the previous commit the system stays up for weeks...
> 
> I just tried today's mainline, and it crashed after 10 minutes:
Please test if this patch fixes the issue:

---
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1822,15 +1822,15 @@ static int invoke_tx_handlers_late(struct ieee80211_tx_data *tx)
  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
  	ieee80211_tx_result res = TX_CONTINUE;
  
+	if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL))
+		CALL_TXH(ieee80211_tx_h_rate_ctrl);
+
  	if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
  		__skb_queue_tail(&tx->skbs, tx->skb);
  		tx->skb = NULL;
  		goto txh_done;
  	}
  
-	if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL))
-		CALL_TXH(ieee80211_tx_h_rate_ctrl);
-
  	CALL_TXH(ieee80211_tx_h_michael_mic_add);
  	CALL_TXH(ieee80211_tx_h_sequence);
  	CALL_TXH(ieee80211_tx_h_fragment);