[RFC][PATCH 06/10] fec: fix uninitialized rx buffer usage

From: Amit Kucheria
Date: Thu Dec 03 2009 - 21:48:30 EST


From: Rob Herring <r.herring@xxxxxxxxxxxxx>

The fec driver was enabling receive buffer descriptor without allocating
the buffers. Make sure the buffer descriptors are initialized to not
start receiving packets.

Signed-off-by: Rob Herring <r.herring@xxxxxxxxxxxxx>
Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
---
drivers/net/fec.c | 57 +++++++++++++++++++++++++++--------------------------
1 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/drivers/net/fec.c b/drivers/net/fec.c
index 16a1d58..9a8743d 100644
--- a/drivers/net/fec.c
+++ b/drivers/net/fec.c
@@ -1658,6 +1658,7 @@ static int fec_enet_init(struct net_device *dev, int index)
{
struct fec_enet_private *fep = netdev_priv(dev);
struct bufdesc *cbd_base;
+ struct bufdesc *bdp;
int i;

/* Allocate memory for buffer descriptors. */
@@ -1710,6 +1711,34 @@ static int fec_enet_init(struct net_device *dev, int index)
/* Set MII speed to 2.5 MHz */
fep->phy_speed = ((((clk_get_rate(fep->clk) / 2 + 4999999)
/ 2500000) / 2) & 0x3F) << 1;
+
+ /* Initialize the receive buffer descriptors. */
+ bdp = fep->rx_bd_base;
+ for (i = 0; i < RX_RING_SIZE; i++) {
+
+ /* Initialize the BD for every fragment in the page. */
+ bdp->cbd_sc = 0;
+ bdp++;
+ }
+
+ /* Set the last buffer to wrap */
+ bdp--;
+ bdp->cbd_sc |= BD_SC_WRAP;
+
+ /* ...and the same for transmit */
+ bdp = fep->tx_bd_base;
+ for (i = 0; i < TX_RING_SIZE; i++) {
+
+ /* Initialize the BD for every fragment in the page. */
+ bdp->cbd_sc = 0;
+ bdp->cbd_bufaddr = 0;
+ bdp++;
+ }
+
+ /* Set the last buffer to wrap */
+ bdp--;
+ bdp->cbd_sc |= BD_SC_WRAP;
+
fec_restart(dev, 0);

/* Queue up command to detect the PHY and initialize the
@@ -1730,7 +1759,6 @@ static void
fec_restart(struct net_device *dev, int duplex)
{
struct fec_enet_private *fep = netdev_priv(dev);
- struct bufdesc *bdp;
int i;

/* Whack a reset. We should wait for this. */
@@ -1768,33 +1796,6 @@ fec_restart(struct net_device *dev, int duplex)
}
}

- /* Initialize the receive buffer descriptors. */
- bdp = fep->rx_bd_base;
- for (i = 0; i < RX_RING_SIZE; i++) {
-
- /* Initialize the BD for every fragment in the page. */
- bdp->cbd_sc = BD_ENET_RX_EMPTY;
- bdp++;
- }
-
- /* Set the last buffer to wrap */
- bdp--;
- bdp->cbd_sc |= BD_SC_WRAP;
-
- /* ...and the same for transmit */
- bdp = fep->tx_bd_base;
- for (i = 0; i < TX_RING_SIZE; i++) {
-
- /* Initialize the BD for every fragment in the page. */
- bdp->cbd_sc = 0;
- bdp->cbd_bufaddr = 0;
- bdp++;
- }
-
- /* Set the last buffer to wrap */
- bdp--;
- bdp->cbd_sc |= BD_SC_WRAP;
-
/* Enable MII mode */
if (duplex) {
/* MII enable / FD enable */
--
1.6.3.3

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