[PATCH net v2] net: stmmac: Fix E2E delay mechanism

[Rohan G Thomas via B4 Relay <devnull+rohan.g.thomas.altera.com@kernel.org>]

From: Rohan G Thomas <rohan.g.thomas@altera.com>

For E2E delay mechanism, "received DELAY_REQ without timestamp" error
messages show up for dwmac v3.70+ and dwxgmac IPs.

This issue affects socfpga platforms, Agilex7 (dwmac 3.70) and
Agilex5 (dwxgmac). According to the databook, to enable timestamping
for all events, the SNAPTYPSEL bits in the MAC_Timestamp_Control
register must be set to 2'b01, and the TSEVNTENA bit must be cleared
to 0'b0.

Commit 3cb958027cb8 ("net: stmmac: Fix E2E delay mechanism") already
addresses this problem for all dwmacs above version v4.10. However,
same holds true for v3.70 and above, as well as for dwxgmac. Updates
the check accordingly.

Fixes: 14f347334bf2 ("net: stmmac: Correctly take timestamp for PTPv2")
Fixes: f2fb6b6275eb ("net: stmmac: enable timestamp snapshot for required PTP packets in dwmac v5.10a")
Fixes: 3cb958027cb8 ("net: stmmac: Fix E2E delay mechanism")
Signed-off-by: Rohan G Thomas <rohan.g.thomas@altera.com>
---
v1 -> v2:
   - Rebased patch to net tree
   - Replace core_type with has_xgmac
   - Nit changes in the commit message
   - Link: https://lore.kernel.org/all/20251125-ext-ptp-fix-v1-1-83f9f069cb36@altera.com/
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 7b90ecd3a55e600458b0c87d6125831626f4683d..cfc6e5aaf6f631b9d00dab9f6339778123d4bc75 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -590,7 +590,8 @@ static int stmmac_hwtstamp_set(struct net_device *dev,
 			config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
 			ptp_v2 = PTP_TCR_TSVER2ENA;
 			snap_type_sel = PTP_TCR_SNAPTYPSEL_1;
-			if (priv->synopsys_id < DWMAC_CORE_4_10)
+			if (priv->synopsys_id < DWMAC_CORE_3_70 &&
+			    !priv->plat->has_xgmac)
 				ts_event_en = PTP_TCR_TSEVNTENA;
 			ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
 			ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;

---
base-commit: 527d39cba164fd11e5a46dc38d8f330c72cf992b
change-id: 20251129-ext-ptp-2v-b2cc3b7baa59

Best regards,
-- 
Rohan G Thomas <rohan.g.thomas@altera.com>