net: stmmac: Fix stmmac_get_rx_hwtstamp()

When using GMAC4 the valid timestamp is from CTX next desc but
we are passing the previous desc to get_rx_timestamp_status()
callback.

Fix this and while at it rework a little bit the function logic.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 7 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index d67638c7078e..284c10720daf 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -473,19 +473,18 @@ static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p,
                                    struct dma_desc *np, struct sk_buff *skb)
 {
         struct skb_shared_hwtstamps *shhwtstamp = NULL;
+        struct dma_desc *desc = p;
         u64 ns;
 
         if (!priv->hwts_rx_en)
                 return;
+        /* For GMAC4, the valid timestamp is from CTX next desc. */
+        if (priv->plat->has_gmac4)
+                desc = np;
 
         /* Check if timestamp is available */
-        if (priv->hw->desc->get_rx_timestamp_status(p, priv->adv_ts)) {
-                /* For GMAC4, the valid timestamp is from CTX next desc. */
-                if (priv->plat->has_gmac4)
-                        ns = priv->hw->desc->get_timestamp(np, priv->adv_ts);
-                else
-                        ns = priv->hw->desc->get_timestamp(p, priv->adv_ts);
-
+        if (priv->hw->desc->get_rx_timestamp_status(desc, 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);
                 memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));