[PATCH net v3] octeontx2-pf: Fix ethtool timestamping capabilities for SDP representors

[nshettyj]

From: Roy Franz <rfranz@xxxxxxxxxxx>

SDP representors do not support hardware timestamping. Fix this by
skipping PTP initialization for SDP representors in otx2_ptp_init(),
similar to how it is already skipped for LBK VFs. This ensures
otx2_get_ts_info() reports only software timestamping capabilities
to userspace.

Also fix otx2_config_hwtstamp_set() to return -EOPNOTSUPP with a
descriptive error message when PTP is not available, and add null
checks for pfvf->ptp and sq->timestamps in otx2_set_txtstamp() to
avoid a potential NULL dereference.

Fixes: 2f7f33a09516 ("octeontx2-pf: Add representors for sdp MAC")
Signed-off-by: Nitin Shetty J <nshettyj@xxxxxxxxxxx>
Signed-off-by: Roy Franz <rfranz@xxxxxxxxxxx>
---
v3:
- In otx2_config_hwtstamp_set(), replace -ENODEV with -EOPNOTSUPP and
  add NL_SET_ERR_MSG_MOD() to provide a descriptive extack error message
  when pfvf->ptp is NULL (hardware timestamping not supported).
- In otx2_set_txtstamp(), add guards for pfvf->ptp and sq->timestamps
  being non-NULL before entering the hardware TX timestamp path, preventing
  a potential NULL pointer dereference on interfaces without PTP support.

v2:
- Disable PTP initialization for SDP representors to cover both
  ethtool capabilities and hwtstamp ioctl handling.
---
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c   | 7 +++++--
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_ptp.c  | 2 +-
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c | 3 ++-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
index c0e2100de1d9..b231f5c6b23f 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
@@ -2532,8 +2532,11 @@ int otx2_config_hwtstamp_set(struct net_device *netdev,
 {
 	struct otx2_nic *pfvf = netdev_priv(netdev);
 
-	if (!pfvf->ptp)
-		return -ENODEV;
+	if (!pfvf->ptp) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Hardware timestamping is not supported");
+		return -EOPNOTSUPP;
+	}
 
 	switch (config->tx_type) {
 	case HWTSTAMP_TX_OFF:
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ptp.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ptp.c
index 95b0a1e7c936..7b0a51f453ce 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ptp.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_ptp.c
@@ -386,7 +386,7 @@ int otx2_ptp_init(struct otx2_nic *pfvf)
 	struct ptp_req *req;
 	int err;
 
-	if (is_otx2_lbkvf(pfvf->pdev)) {
+	if (is_otx2_lbkvf(pfvf->pdev) || is_otx2_sdp_rep(pfvf->pdev)) {
 		pfvf->ptp = NULL;
 		return 0;
 	}
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
index 8d2d607bc92f..94da021d452e 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
@@ -1135,7 +1135,8 @@ static void otx2_set_txtstamp(struct otx2_nic *pfvf, struct sk_buff *skb,
 	__wsum skb_csum;
 	u64 iova;
 
-	if (unlikely(!skb_shinfo(skb)->gso_size &&
+	if (unlikely(pfvf->ptp && sq->timestamps &&
+		     !skb_shinfo(skb)->gso_size &&
 		     (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))) {
 		if (unlikely(pfvf->flags & OTX2_FLAG_PTP_ONESTEP_SYNC &&
 			     otx2_ptp_is_sync(skb, &ptp_offset, &udp_csum_crt))) {
-- 
2.48.1