[PATCH net 5/8] net: bcmgenet: acquire ring lock with BH disabled in bcmgenet_dump_tx_queue

[Florian Fainelli <florian.fainelli@broadcom.com>]

bcmgenet_dump_tx_queue() is called from bcmgenet_timeout() in process or
timer context and acquires ring->lock using spin_lock(). If a softirq
such as TX NAPI (bcmgenet_tx_poll()) fires on the same CPU while the lock
is held, it will deadlock trying to acquire ring->lock.

Use spin_lock_bh() and spin_unlock_bh() in bcmgenet_dump_tx_queue(),
matching bcmgenet_tx_reclaim().

Fixes: 13ea657806cf ("net: bcmgenet: improve TX timeout")
Assisted-by: LLM
Co-authored-by: Cursor <cursoragent@cursor.com>
Change-Id: I0c4c6392590b2d16abd44f75d3f6974f3e1b874b
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index ef155a170fa6..799da63e3a4e 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3508,14 +3508,14 @@ static void bcmgenet_dump_tx_queue(struct bcmgenet_tx_ring *ring)
 
 	txq = netdev_get_tx_queue(priv->dev, ring->index);
 
-	spin_lock(&ring->lock);
+	spin_lock_bh(&ring->lock);
 	intsts = ~bcmgenet_intrl2_1_readl(priv, INTRL2_CPU_MASK_STATUS);
 	intmsk = 1 << ring->index;
 	c_index = bcmgenet_tdma_ring_readl(priv, ring->index, TDMA_CONS_INDEX);
 	p_index = bcmgenet_tdma_ring_readl(priv, ring->index, TDMA_PROD_INDEX);
 	txq_stopped = netif_tx_queue_stopped(txq);
 	free_bds = ring->free_bds;
-	spin_unlock(&ring->lock);
+	spin_unlock_bh(&ring->lock);
 
 	netif_err(priv, tx_err, priv->dev, "Ring %d queue %d status summary\n"
 		  "TX queue status: %s, interrupts: %s\n"
-- 
2.34.1