From 3601e3ae4357d48b3294f42781d0f19095d1b00e Mon Sep 17 00:00:00 2001
Message-Id: <3601e3ae4357d48b3294f42781d0f19095d1b00e.1564479382.git.joabreu@synopsys.com>
From: Jose Abreu <joabreu@synopsys.com>
Date: Tue, 30 Jul 2019 11:36:13 +0200
Subject: [PATCH net] net: stmmac: Sync RX Buffer upon allocation

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
---
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: netdev@vger.kernel.org
Cc: linux-stm32@st-md-mailman.stormreply.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 98b1a5c6d537..9a4a56ad35cd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3271,9 +3271,11 @@ static inline int stmmac_rx_threshold_count(struct stmmac_rx_queue *rx_q)
 static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue)
 {
 	struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
-	int dirty = stmmac_rx_dirty(priv, queue);
+	int len, dirty = stmmac_rx_dirty(priv, queue);
 	unsigned int entry = rx_q->dirty_rx;
 
+	len = DIV_ROUND_UP(priv->dma_buf_sz, PAGE_SIZE) * PAGE_SIZE;
+
 	while (dirty-- > 0) {
 		struct stmmac_rx_buffer *buf = &rx_q->buf_pool[entry];
 		struct dma_desc *p;
@@ -3291,6 +3293,13 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue)
 		}
 
 		buf->addr = page_pool_get_dma_addr(buf->page);
+
+		/* Sync whole allocation to device. This will invalidate old
+		 * data.
+		 */
+		dma_sync_single_for_device(priv->device, buf->addr, len,
+					   DMA_FROM_DEVICE);
+
 		stmmac_set_desc_addr(priv, p, buf->addr);
 		stmmac_refill_desc3(priv, rx_q, p);
 
@@ -3425,8 +3434,6 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
 			skb_copy_to_linear_data(skb, page_address(buf->page),
 						frame_len);
 			skb_put(skb, frame_len);
-			dma_sync_single_for_device(priv->device, buf->addr,
-						   frame_len, DMA_FROM_DEVICE);
 
 			if (netif_msg_pktdata(priv)) {
 				netdev_dbg(priv->dev, "frame received (%dbytes)",
-- 
2.7.4

