3 files changed, 69 insertions, 2 deletions

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
index 8b79d88480db..39da2f811858 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
@@ -1277,6 +1277,10 @@ static int xgbe_start(struct xgbe_prv_data *pdata)
 
 	hw_if->enable_tx(pdata);
 	hw_if->enable_rx(pdata);
+	/* Synchronize flag with hardware state after enabling TX/RX.
+	 * This prevents stale state after device restart cycles.
+	 */
+	pdata->data_path_stopped = false;
 
 	udp_tunnel_nic_reset_ntf(netdev);
 
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
index 13c556dc0d67..b8cf6ccfe641 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
@@ -2017,6 +2017,48 @@ rx_adapt_reinit:
 	xgbe_rx_adaptation(pdata);
 }
 
+/*
+ * xgbe_phy_stop_data_path - Stop TX/RX to prevent packet corruption
+ * @pdata: driver private data
+ *
+ * This function stops the data path (TX and RX) to prevent packet
+ * corruption during critical PHY operations like RX adaptation.
+ * Must be called before initiating RX adaptation when link goes down.
+ */
+static void xgbe_phy_stop_data_path(struct xgbe_prv_data *pdata)
+{
+	if (pdata->data_path_stopped)
+		return;
+
+	/* Stop TX/RX to prevent packet corruption during RX adaptation */
+	pdata->hw_if.disable_tx(pdata);
+	pdata->hw_if.disable_rx(pdata);
+	pdata->data_path_stopped = true;
+
+	netif_dbg(pdata, link, pdata->netdev,
+		  "stopping data path for RX adaptation\n");
+}
+
+/*
+ * xgbe_phy_start_data_path - Re-enable TX/RX after RX adaptation
+ * @pdata: driver private data
+ *
+ * This function re-enables the data path (TX and RX) after RX adaptation
+ * has completed successfully. Only called when link is confirmed up.
+ */
+static void xgbe_phy_start_data_path(struct xgbe_prv_data *pdata)
+{
+	if (!pdata->data_path_stopped)
+		return;
+
+	pdata->hw_if.enable_rx(pdata);
+	pdata->hw_if.enable_tx(pdata);
+	pdata->data_path_stopped = false;
+
+	netif_dbg(pdata, link, pdata->netdev,
+		  "restarting data path after RX adaptation\n");
+}
+
 static void xgbe_phy_rx_reset(struct xgbe_prv_data *pdata)
 {
 	int reg;
@@ -2810,13 +2852,27 @@ static int xgbe_phy_link_status(struct xgbe_prv_data *pdata, int *an_restart)
 	if (pdata->en_rx_adap) {
 		/* if the link is available and adaptation is done,
 		 * declare link up
+		 *
+		 * Note: When link is up and adaptation is done, we can
+		 * safely re-enable the data path if it was stopped
+		 * for adaptation.
 		 */
-		if ((reg & MDIO_STAT1_LSTATUS) && pdata->rx_adapt_done)
+		if ((reg & MDIO_STAT1_LSTATUS) && pdata->rx_adapt_done) {
+			xgbe_phy_start_data_path(pdata);
 			return 1;
+		}
 		/* If either link is not available or adaptation is not done,
 		 * retrigger the adaptation logic. (if the mode is not set,
 		 * then issue mailbox command first)
 		 */
+
+		/* CRITICAL: Stop data path BEFORE triggering RX adaptation
+		 * to prevent CRC errors from packets corrupted during
+		 * the adaptation process. This is especially important
+		 * when AN is OFF in 10G KR mode.
+		 */
+		xgbe_phy_stop_data_path(pdata);
+
 		if (pdata->mode_set) {
 			xgbe_phy_rx_adaptation(pdata);
 		} else {
@@ -2824,8 +2880,11 @@ static int xgbe_phy_link_status(struct xgbe_prv_data *pdata, int *an_restart)
 			xgbe_phy_set_mode(pdata, phy_data->cur_mode);
 		}
 
-		if (pdata->rx_adapt_done)
+		if (pdata->rx_adapt_done) {
+			/* Adaptation complete, safe to re-enable data path */
+			xgbe_phy_start_data_path(pdata);
 			return 1;
+		}
 	} else if (reg & MDIO_STAT1_LSTATUS)
 		return 1;
 
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe.h b/drivers/net/ethernet/amd/xgbe/xgbe.h
index e1d7d7150e16..438033a71523 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe.h
+++ b/drivers/net/ethernet/amd/xgbe/xgbe.h
@@ -1243,6 +1243,10 @@ struct xgbe_prv_data {
 	bool en_rx_adap;
 	int rx_adapt_retries;
 	bool rx_adapt_done;
+	/* Flag to track if data path (TX/RX) was stopped for RX adaptation.
+	 * This prevents packet corruption during the adaptation window.
+	 */
+	bool data_path_stopped;
 	bool mode_set;
 	bool sph;
 };