[PATCH net 1/2] net: stmmac: RX Descriptors need to be clean before setting buffers

From: Jose Abreu
Date: Mon Jul 22 2019 - 04:40:05 EST


RX Descriptors are being cleaned after setting the buffers which may
lead to buffer addresses being wiped out.

Fix this by clearing earlier the RX Descriptors.

Fixes: 2af6106ae949 ("net: stmmac: Introducing support for Page Pool")
Signed-off-by: Jose Abreu <joabreu@xxxxxxxxxxxx>

---
Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Cc: Jose Abreu <joabreu@xxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c7c9e5f162e6..5f1294ce0216 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1295,6 +1295,8 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
"(%s) dma_rx_phy=0x%08x\n", __func__,
(u32)rx_q->dma_rx_phy);

+ stmmac_clear_rx_descriptors(priv, queue);
+
for (i = 0; i < DMA_RX_SIZE; i++) {
struct dma_desc *p;

@@ -1312,8 +1314,6 @@ static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
rx_q->cur_rx = 0;
rx_q->dirty_rx = (unsigned int)(i - DMA_RX_SIZE);

- stmmac_clear_rx_descriptors(priv, queue);
-
/* Setup the chained descriptor addresses */
if (priv->mode == STMMAC_CHAIN_MODE) {
if (priv->extend_desc)
--
2.7.4