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authorLennert Buytenhek <buytenh@wantstofly.org>2008-08-24 02:45:32 +0200
committerLennert Buytenhek <buytenh@marvell.com>2008-08-24 03:32:56 +0200
commit819ddcafb33136f2ba18018a22edcf857f640528 (patch)
treee9cffe7c32e761da3a495bd51d1a9d5929a803dc /drivers/net
parent6a55617ed5d1aa62b850de2cf66f5ede2eef4825 (diff)
downloadop-kernel-dev-819ddcafb33136f2ba18018a22edcf857f640528.zip
op-kernel-dev-819ddcafb33136f2ba18018a22edcf857f640528.tar.gz
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 <buytenh@marvell.com>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/mv643xx_eth.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 46819af..af279f2 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));
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