[PATCH] net: sunplus: fix tx_poll spin_lock missing irqsave in NAPI context

[PATCH] net: sunplus: fix tx_poll spin_lock missing irqsave in NAPI context

[Andrew Gaylard]

spl2sw_tx_poll() runs in NAPI (softirq) context and acquires
comm->tx_lock with plain spin_lock(). The hardirq handler
spl2sw_ethernet_interrupt() acquires the same lock, so a hardirq on
the same CPU while the NAPI poll holds the lock would deadlock with
IRQs disabled. Use spin_lock_irqsave/spin_unlock_irqrestore.

Signed-off-by: Andrew Gaylard <ag@ffroot.co.za>
---
 drivers/net/ethernet/sunplus/spl2sw_int.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/sunplus/spl2sw_int.c b/drivers/net/ethernet/sunplus/spl2sw_int.c
index a37c9a4c281f..7e07cd941434 100644
--- a/drivers/net/ethernet/sunplus/spl2sw_int.c
+++ b/drivers/net/ethernet/sunplus/spl2sw_int.c
@@ -147,7 +147,7 @@ int spl2sw_tx_poll(struct napi_struct *napi, int budget)
 	u32 cmd;
 	int i;
 
-	spin_lock(&comm->tx_lock);
+	spin_lock_irqsave(&comm->tx_lock, flags);
 
 	tx_done_pos = comm->tx_done_pos;
 	while (((tx_done_pos != comm->tx_pos) || (comm->tx_desc_full == 1)) && budget_left) {
@@ -196,7 +196,7 @@ int spl2sw_tx_poll(struct napi_struct *napi, int budget)
 				if (netif_queue_stopped(comm->ndev[i]))
 					netif_wake_queue(comm->ndev[i]);
 
-	spin_unlock(&comm->tx_lock);
+	spin_unlock_irqrestore(&comm->tx_lock, flags);
 
 	spin_lock_irqsave(&comm->int_mask_lock, flags);
 	mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
-- 
2.53.0