Re: [PATCH 2/2] net: ethernet: stmmac: remove private tx queue lock

On Thu 2016-12-08 10:26:41, David Miller wrote:

From: Pavel Machek <redacted>
Date: Thu, 8 Dec 2016 15:08:46 +0100

quoted

On Wed 2016-12-07 18:41:11, David Miller wrote:

quoted

From: Pavel Machek <redacted>
Date: Wed, 7 Dec 2016 22:37:57 +0100

quoted

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 982c952..7415bc2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1308,7 +1308,7 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
 	unsigned int bytes_compl = 0, pkts_compl = 0;
 	unsigned int entry = priv->dirty_tx;
 
-	spin_lock(&priv->tx_lock);
+	netif_tx_lock_bh(priv->dev);
 
 	priv->xstats.tx_clean++;
 

stmmac_tx_clean() runs from either the timer or the NAPI poll handler,
both execute from software interrupts, therefore _bh() should be
unnecessary.

I've tried the test again with netif_tx_lock() (not _bh()) and it
survived for more then four hours. Strange...

It's not strange, it's completely expected.

Well, I tried that exact test before, and it survived for something
like 10 minutes. So yes... this surprised me.
									Pavel

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