[PATCH net-next 2/3] net: stmmac: Fix stmmac_get_rx_hwtstamp()

[Jose Abreu]

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 <joab...@synopsys.com>
Cc: David S. Miller <da...@davemloft.net>
Cc: Joao Pinto <jpi...@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavall...@st.com>
Cc: Alexandre Torgue <alexandre.tor...@st.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 ++++++-------
 1 file 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 f7b7906..0d3fd3b 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));
-- 
1.9.1