[PATCH AUTOSEL for 4.14 040/110] net: stmmac: Fix bad RX timestamp extraction

[Sasha Levin]

From: Fredrik Hallenberg <megahallon@xxxxxxxxx>

[ Upstream commit a1762456993893795030d911106a7650481db0ef ]

As noted in dwmac4_wrback_get_rx_timestamp_status the timestamp is found
in the context descriptor following the current descriptor. However the
current code looks for the context descriptor in the current
descriptor, which will always fail.

Signed-off-by: Fredrik Hallenberg <megahallon@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/common.h       | 2 +-
 drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c | 5 +++--
 drivers/net/ethernet/stmicro/stmmac/enh_desc.c     | 3 ++-
 drivers/net/ethernet/stmicro/stmmac/norm_desc.c    | 2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  | 2 +-
 5 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index e82b4b70b7be..627fec210e2f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -409,7 +409,7 @@ struct stmmac_desc_ops {
 	/* get timestamp value */
 	 u64(*get_timestamp) (void *desc, u32 ats);
 	/* get rx timestamp status */
-	int (*get_rx_timestamp_status) (void *desc, u32 ats);
+	int (*get_rx_timestamp_status)(void *desc, void *next_desc, u32 ats);
 	/* Display ring */
 	void (*display_ring)(void *head, unsigned int size, bool rx);
 	/* set MSS via context descriptor */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
index 4b286e27c4ca..7e089bf906b4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c
@@ -258,7 +258,8 @@ static int dwmac4_rx_check_timestamp(void *desc)
 	return ret;
 }
 
-static int dwmac4_wrback_get_rx_timestamp_status(void *desc, u32 ats)
+static int dwmac4_wrback_get_rx_timestamp_status(void *desc, void *next_desc,
+						 u32 ats)
 {
 	struct dma_desc *p = (struct dma_desc *)desc;
 	int ret = -EINVAL;
@@ -270,7 +271,7 @@ static int dwmac4_wrback_get_rx_timestamp_status(void *desc, u32 ats)
 
 			/* Check if timestamp is OK from context descriptor */
 			do {
-				ret = dwmac4_rx_check_timestamp(desc);
+				ret = dwmac4_rx_check_timestamp(next_desc);
 				if (ret < 0)
 					goto exit;
 				i++;
diff --git a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
index 7546b3664113..2a828a312814 100644
--- a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
@@ -400,7 +400,8 @@ static u64 enh_desc_get_timestamp(void *desc, u32 ats)
 	return ns;
 }
 
-static int enh_desc_get_rx_timestamp_status(void *desc, u32 ats)
+static int enh_desc_get_rx_timestamp_status(void *desc, void *next_desc,
+					    u32 ats)
 {
 	if (ats) {
 		struct dma_extended_desc *p = (struct dma_extended_desc *)desc;
diff --git a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
index f817f8f36569..db4cee57bb24 100644
--- a/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/norm_desc.c
@@ -265,7 +265,7 @@ static u64 ndesc_get_timestamp(void *desc, u32 ats)
 	return ns;
 }
 
-static int ndesc_get_rx_timestamp_status(void *desc, u32 ats)
+static int ndesc_get_rx_timestamp_status(void *desc, void *next_desc, u32 ats)
 {
 	struct dma_desc *p = (struct dma_desc *)desc;
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0ad12c81a9e4..d0cc73795056 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -489,7 +489,7 @@ static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p,
 		desc = np;
 
 	/* Check if timestamp is available */
-	if (priv->hw->desc->get_rx_timestamp_status(desc, priv->adv_ts)) {
+	if (priv->hw->desc->get_rx_timestamp_status(p, np, priv->adv_ts)) {
 		ns = priv->hw->desc->get_timestamp(desc, priv->adv_ts);
 		netdev_dbg(priv->dev, "get valid RX hw timestamp %llu\n", ns);
 		shhwtstamp = skb_hwtstamps(skb);
-- 
2.11.0