Re: [PATCH net-next v3 1/9] tsnep: Use spin_lock_bh for TX
From: Alexander Lobakin <hidden>
Date: 2023-01-05 12:40:32
From: Gerhard Engleder <redacted> Date: Wed Jan 04 2023 20:41:24 GMT+0100
TX processing is done only within process or BH context. Therefore, _irqsafe variant is not necessary.
NAPI and .ndo_{start,xdp}_xmit are BH-only, where can the process
context happen here?
quoted hunk ↗ jump to hunk
Signed-off-by: Gerhard Engleder <redacted> --- drivers/net/ethernet/engleder/tsnep_main.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-)diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c index bf0190e1d2ea..7cc5e2407809 100644 --- a/drivers/net/ethernet/engleder/tsnep_main.c +++ b/drivers/net/ethernet/engleder/tsnep_main.c@@ -434,7 +434,6 @@ static int tsnep_tx_unmap(struct tsnep_tx *tx, int index, int count) static netdev_tx_t tsnep_xmit_frame_ring(struct sk_buff *skb, struct tsnep_tx *tx) { - unsigned long flags; int count = 1; struct tsnep_tx_entry *entry; int length;@@ -444,7 +443,7 @@ static netdev_tx_t tsnep_xmit_frame_ring(struct sk_buff *skb, if (skb_shinfo(skb)->nr_frags > 0) count += skb_shinfo(skb)->nr_frags; - spin_lock_irqsave(&tx->lock, flags); + spin_lock_bh(&tx->lock); if (tsnep_tx_desc_available(tx) < count) { /* ring full, shall not happen because queue is stopped if full@@ -452,7 +451,7 @@ static netdev_tx_t tsnep_xmit_frame_ring(struct sk_buff *skb, */ netif_stop_queue(tx->adapter->netdev); - spin_unlock_irqrestore(&tx->lock, flags); + spin_unlock_bh(&tx->lock); return NETDEV_TX_BUSY; }@@ -468,7 +467,7 @@ static netdev_tx_t tsnep_xmit_frame_ring(struct sk_buff *skb, tx->dropped++; - spin_unlock_irqrestore(&tx->lock, flags); + spin_unlock_bh(&tx->lock); netdev_err(tx->adapter->netdev, "TX DMA map failed\n");@@ -496,20 +495,19 @@ static netdev_tx_t tsnep_xmit_frame_ring(struct sk_buff *skb, netif_stop_queue(tx->adapter->netdev); } - spin_unlock_irqrestore(&tx->lock, flags); + spin_unlock_bh(&tx->lock); return NETDEV_TX_OK; } static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget) { - unsigned long flags; int budget = 128; struct tsnep_tx_entry *entry; int count; int length; - spin_lock_irqsave(&tx->lock, flags); + spin_lock_bh(&tx->lock); do { if (tx->read == tx->write)@@ -568,18 +566,17 @@ static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget) netif_wake_queue(tx->adapter->netdev); } - spin_unlock_irqrestore(&tx->lock, flags); + spin_unlock_bh(&tx->lock); return (budget != 0); } static bool tsnep_tx_pending(struct tsnep_tx *tx) { - unsigned long flags; struct tsnep_tx_entry *entry; bool pending = false; - spin_lock_irqsave(&tx->lock, flags); + spin_lock_bh(&tx->lock); if (tx->read != tx->write) { entry = &tx->entry[tx->read];@@ -589,7 +586,7 @@ static bool tsnep_tx_pending(struct tsnep_tx *tx) pending = true; } - spin_unlock_irqrestore(&tx->lock, flags); + spin_unlock_bh(&tx->lock); return pending; }
Thanks, Olek