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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-DetectorID-Processed: b00c1d49-9d2e-4205-b15f-d015386d3d5e On 8/26/25 01:24, Mike Galbraith wrote: > Lockdep reports ring->lock to not be irq safe during netpoll/netconsole > session, resulting in a potential deadlock scenario. > > Chain exists of: > &host->lock --> target_list_lock --> &ring->lock > Possible interrupt unsafe locking scenario: > CPU0 CPU1 > ---- ---- > lock(&ring->lock); > local_irq_disable(); > lock(&host->lock); > lock(target_list_lock); > > lock(&host->lock); > *** DEADLOCK *** > > Prevent that via use of irqsave/restore spinlock variant when polling. > > Signed-off-by: Mike Galbraith Your patch did not make it to the adequate mailing list which should be at least netdev@vger.kernel.org. This is effectively a partial revert of b0447ecb533270cf857ebee1133cb8ff67115423 ("net: bcmgenet: relax lock constraints to reduce IRQ latency") therefore I would want Doug to chime in and review this. Thanks! > --- > drivers/net/ethernet/broadcom/genet/bcmgenet.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c > +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c > @@ -2022,14 +2022,15 @@ static int bcmgenet_tx_poll(struct napi_ > container_of(napi, struct bcmgenet_tx_ring, napi); > unsigned int work_done = 0; > struct netdev_queue *txq; > + unsigned long flags; > > - spin_lock(&ring->lock); > + spin_lock_irqsave(&ring->lock, flags); > work_done = __bcmgenet_tx_reclaim(ring->priv->dev, ring); > if (ring->free_bds > (MAX_SKB_FRAGS + 1)) { > txq = netdev_get_tx_queue(ring->priv->dev, ring->index); > netif_tx_wake_queue(txq); > } > - spin_unlock(&ring->lock); > + spin_unlock_irqrestore(&ring->lock, flags); > > if (work_done == 0) { > napi_complete(napi); > @@ -2128,6 +2129,7 @@ static netdev_tx_t bcmgenet_xmit(struct > struct bcmgenet_tx_ring *ring = NULL; > struct enet_cb *tx_cb_ptr; > struct netdev_queue *txq; > + unsigned long flags; > int nr_frags, index; > dma_addr_t mapping; > unsigned int size; > @@ -2149,7 +2151,7 @@ static netdev_tx_t bcmgenet_xmit(struct > > nr_frags = skb_shinfo(skb)->nr_frags; > > - spin_lock(&ring->lock); > + spin_lock_irqsave(&ring->lock, flags); > if (ring->free_bds <= (nr_frags + 1)) { > if (!netif_tx_queue_stopped(txq)) > netif_tx_stop_queue(txq); > @@ -2239,7 +2241,7 @@ static netdev_tx_t bcmgenet_xmit(struct > bcmgenet_tdma_ring_writel(priv, ring->index, > ring->prod_index, TDMA_PROD_INDEX); > out: > - spin_unlock(&ring->lock); > + spin_unlock_irqrestore(&ring->lock, flags); > > return ret; > > -- Florian