[PATCH wireless v2 3/4] wifi: b43: Stop correct queue in DMA worker when QoS is disabled

From: Rahul Rameshbabu <sergeantsagara@protonmail.com>
To: "Kalle Valo" <kvalo@kernel.org>,
	"Larry Finger" <Larry.Finger@lwfinger.net>,
	"Michael Büsch" <m@bues.ch>,
	"Julian Calaby" <julian.calaby@gmail.com>
Cc: linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Rahul Rameshbabu <sergeantsagara@protonmail.com>
Subject: [PATCH wireless v2 3/4] wifi: b43: Stop correct queue in DMA worker when QoS is disabled
Date: Sun, 31 Dec 2023 05:03:51 +0000	[thread overview]
Message-ID: <20231231050300.122806-4-sergeantsagara@protonmail.com> (raw)
In-Reply-To: <20231231050300.122806-1-sergeantsagara@protonmail.com>

When QoS is disabled, the queue priority value will not map to the correct
ieee80211 queue since there is only one queue. Stop queue 0 when QoS is
disabled to prevent trying to stop a non-existent queue and failing to stop
the actual queue instantiated.

Fixes: bad691946966 ("b43: avoid packet losses in the dma worker code.")
Signed-off-by: Rahul Rameshbabu <sergeantsagara@protonmail.com>
---

Notes:
    Changes:
    
        v1->v2:
            - Refactored logic with helpers (suggested by Larry Finger
              <Larry.Finger@lwfinger.net>)
    
    Issue Details:
    
        When QoS was first introduced to the b43 driver in commit
        e6f5b934fba8 ("b43: Add QOS support"), four rings were allocated for
        different QoS priorities for video, voice, best effort, and background.
        The core networking stack maps these priorities in the skb, and these
        mappings are noted in the ring's queue_prio member. When disabling QoS
        in the driver, the skb will still contain the mapping for the core
        stack while only one queue is actually considered active (the best
        effort queue). In the situation that QoS is disabled, b43 needs to pass
        0 to ieee80211 queue functions since the number of queues is set to 1
        in the struct ieee80211_hw queues member. This issue was then extended
        to the changes in commit bad691946966 ("b43: avoid packet losses in the
        dma worker code.").

 drivers/net/wireless/broadcom/b43/main.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/broadcom/b43/main.c b/drivers/net/wireless/broadcom/b43/main.c
index 92ca0b2ca286..97d8bdeaa06c 100644
--- a/drivers/net/wireless/broadcom/b43/main.c
+++ b/drivers/net/wireless/broadcom/b43/main.c
@@ -3603,7 +3603,7 @@ static void b43_tx_work(struct work_struct *work)
 				err = b43_dma_tx(dev, skb);
 			if (err == -ENOSPC) {
 				wl->tx_queue_stopped[queue_num] = true;
-				ieee80211_stop_queue(wl->hw, queue_num);
+				b43_stop_queue(dev, queue_num);
 				skb_queue_head(&wl->tx_queue[queue_num], skb);
 				break;
 			}
@@ -3627,6 +3627,7 @@ static void b43_op_tx(struct ieee80211_hw *hw,
 		      struct sk_buff *skb)
 {
 	struct b43_wl *wl = hw_to_b43_wl(hw);
+	u16 skb_queue_mapping;
 
 	if (unlikely(skb->len < 2 + 2 + 6)) {
 		/* Too short, this can't be a valid frame. */
@@ -3635,12 +3636,12 @@ static void b43_op_tx(struct ieee80211_hw *hw,
 	}
 	B43_WARN_ON(skb_shinfo(skb)->nr_frags);
 
-	skb_queue_tail(&wl->tx_queue[skb->queue_mapping], skb);
-	if (!wl->tx_queue_stopped[skb->queue_mapping]) {
+	skb_queue_mapping = skb_get_queue_mapping(skb);
+	skb_queue_tail(&wl->tx_queue[skb_queue_mapping], skb);
+	if (!wl->tx_queue_stopped[skb_queue_mapping])
 		ieee80211_queue_work(wl->hw, &wl->tx_work);
-	} else {
-		ieee80211_stop_queue(wl->hw, skb->queue_mapping);
-	}
+	else
+		b43_stop_queue(wl->current_dev, skb_queue_mapping);
 }
 
 static void b43_qos_params_upload(struct b43_wldev *dev,
-- 
2.42.0


