From 819ddcafb33136f2ba18018a22edcf857f640528 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Sun, 24 Aug 2008 02:45:32 +0200 Subject: [PATCH] mv643xx_eth: fix NAPI 'rotting packet' issue When a receive interrupt occurs, mv643xx_eth would first process the receive descriptors and then ACK the receive interrupt, instead of the other way round. This would leave a small race window between processing the last receive descriptor and clearing the receive interrupt status in which a new packet could come in, which would then 'rot' in the receive ring until the next receive interrupt would come in. Fix this by ACKing (clearing) the receive interrupt condition before processing the receive descriptors. Signed-off-by: Lennert Buytenhek --- drivers/net/mv643xx_eth.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c index 46819af3b062..af279f26c407 100644 --- a/drivers/net/mv643xx_eth.c +++ b/drivers/net/mv643xx_eth.c @@ -650,8 +650,6 @@ static int mv643xx_eth_poll(struct napi_struct *napi, int budget) if (rx < budget) { netif_rx_complete(mp->dev, napi); - wrl(mp, INT_CAUSE(mp->port_num), 0); - wrl(mp, INT_CAUSE_EXT(mp->port_num), 0); wrl(mp, INT_MASK(mp->port_num), INT_TX_END | INT_RX | INT_EXT); } @@ -1796,6 +1794,7 @@ static irqreturn_t mv643xx_eth_irq(int irq, void *dev_id) */ #ifdef MV643XX_ETH_NAPI if (int_cause & INT_RX) { + wrl(mp, INT_CAUSE(mp->port_num), ~(int_cause & INT_RX)); wrl(mp, INT_MASK(mp->port_num), 0x00000000); rdl(mp, INT_MASK(mp->port_num));