[PATCH net 09/11] net: au1000: restore RX buffer addresses when restarting the MAC

[Florian Fainelli]

The MAC DMA engine updates each receive descriptor's address as it
transfers data. Clearing the descriptor control bits during reset does
not restore the buffer's starting address.

au1000_init() only set RX_DMA_ENABLE on the address left in the
descriptor. After closing and reopening the interface, a receive could
therefore start partway through its buffer and overwrite memory beyond
the allocation.

Reload each RX descriptor from rx_db_inuse before enabling it, as the
receive completion path already does.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
 drivers/net/ethernet/amd/au1000_eth.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amd/au1000_eth.c b/drivers/net/ethernet/amd/au1000_eth.c
index 6b817d18329b..8c2dbf72652e 100644
--- a/drivers/net/ethernet/amd/au1000_eth.c
+++ b/drivers/net/ethernet/amd/au1000_eth.c
@@ -722,7 +722,8 @@ static int au1000_init(struct net_device *dev)
 
 
 	for (i = 0; i < NUM_RX_DMA; i++)
-		aup->rx_dma_ring[i]->buff_stat |= RX_DMA_ENABLE;
+		writel(lower_32_bits(aup->rx_db_inuse[i]->dma_addr) |
+		       RX_DMA_ENABLE, &aup->rx_dma_ring[i]->buff_stat);
 
 	wmb(); /* drain writebuffer */
 
-- 
2.53.0