[PATCH v6 net-next 14/17] net: enetc: move sync packet modification before dma_map_single()

[Wei Fang <wei.fang@nxp.com>]

Move sync packet content modification before dma_map_single() to follow
correct DMA usage process, even though the previous sequence worked due
to hardware DMA-coherence support (LS1028A). But for the upcoming i.MX95,
its ENETC (v4) does not support "dma-coherent", so this step is very
necessary. Otherwise, the originTimestamp and correction fields of the
sent packets will still be the values before the modification.

Signed-off-by: Wei Fang <wei.fang@nxp.com>

---
v6 changes:
new patch, separated from the patch "net: enetc: add PTP synchronization
support for ENETC v4"
---
 drivers/net/ethernet/freescale/enetc/enetc.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 4325eb3d9481..25379ac7d69d 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -303,6 +303,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
 	unsigned int f;
 	dma_addr_t dma;
 	u8 flags = 0;
+	u32 tstamp;
 
 	enetc_clear_tx_bd(&temp_bd);
 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
@@ -327,6 +328,13 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
 		}
 	}
 
+	if (enetc_cb->flag & ENETC_F_TX_ONESTEP_SYNC_TSTAMP) {
+		do_onestep_tstamp = true;
+		tstamp = enetc_update_ptp_sync_msg(priv, skb);
+	} else if (enetc_cb->flag & ENETC_F_TX_TSTAMP) {
+		do_twostep_tstamp = true;
+	}
+
 	i = tx_ring->next_to_use;
 	txbd = ENETC_TXBD(*tx_ring, i);
 	prefetchw(txbd);
@@ -346,11 +354,6 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
 	count++;
 
 	do_vlan = skb_vlan_tag_present(skb);
-	if (enetc_cb->flag & ENETC_F_TX_ONESTEP_SYNC_TSTAMP)
-		do_onestep_tstamp = true;
-	else if (enetc_cb->flag & ENETC_F_TX_TSTAMP)
-		do_twostep_tstamp = true;
-
 	tx_swbd->do_twostep_tstamp = do_twostep_tstamp;
 	tx_swbd->qbv_en = !!(priv->active_offloads & ENETC_F_QBV);
 	tx_swbd->check_wb = tx_swbd->do_twostep_tstamp || tx_swbd->qbv_en;
@@ -393,8 +396,6 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
 		}
 
 		if (do_onestep_tstamp) {
-			u32 tstamp = enetc_update_ptp_sync_msg(priv, skb);
-
 			/* Configure extension BD */
 			temp_bd.ext.tstamp = cpu_to_le32(tstamp);
 			e_flags |= ENETC_TXBD_E_FLAGS_ONE_STEP_PTP;
-- 
2.34.1