[PATCH net] net: ethtool: let tsconfig reach a PHY-only timestamp provider

[Nicolai Buchwitz]

TSCONFIG_GET and TSCONFIG_SET reject a device that implements neither
hwtstamp NDO, even when its PHY can serve the request. The ioctls they
meant to replace handle it, so the two interfaces disagree on the same
hardware and user space has to pick one.

Drop both checks and let the phylib helpers decide, like the ioctls do.

As this makes a netdev provider reachable without ndo_hwtstamp_get, test
for the callback before calling it.

Fixes: 6e9e2eed4f39 ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config")
Signed-off-by: Nicolai Buchwitz <nb@xxxxxxxxxxx>
---
Follow-up to 31995571219c ("net: don't require the hwtstamp NDOs when a
PHY provides timestamping"), which fixed the ioctl side:

  https://lore.kernel.org/netdev/20260918095540.34286-1-nb@xxxxxxxxxxx/

Tested on a Raspberry Pi CM4 with BCM54213PE.

 net/core/dev_ioctl.c   |  3 ++-
 net/ethtool/tsconfig.c | 15 ---------------
 2 files changed, 2 insertions(+), 16 deletions(-)

diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c
index 164643140a52..f6029f60c1dc 100644
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -267,7 +267,8 @@ int dev_get_hwtstamp_phylib(struct net_device *dev,
 		    hwprov->phydev)
 			return phy_hwtstamp_get(hwprov->phydev, cfg);
 
-		if (hwprov->source == HWTSTAMP_SOURCE_NETDEV)
+		if (hwprov->source == HWTSTAMP_SOURCE_NETDEV &&
+		    dev->netdev_ops->ndo_hwtstamp_get)
 			return dev->netdev_ops->ndo_hwtstamp_get(dev, cfg);
 
 		return -EOPNOTSUPP;
diff --git a/net/ethtool/tsconfig.c b/net/ethtool/tsconfig.c
index 6be3aa5d4bc1..8c99b2dc26d0 100644
--- a/net/ethtool/tsconfig.c
+++ b/net/ethtool/tsconfig.c
@@ -42,9 +42,6 @@ static int tsconfig_prepare_data(const struct ethnl_req_info *req_base,
 	struct kernel_hwtstamp_config cfg = {};
 	int ret;
 
-	if (!dev->netdev_ops->ndo_hwtstamp_get)
-		return -EOPNOTSUPP;
-
 	ret = ethnl_ops_begin(dev);
 	if (ret < 0)
 		return ret;
@@ -248,17 +245,6 @@ static int tsconfig_send_reply(struct net_device *dev, struct genl_info *info)
 	return ret;
 }
 
-static int ethnl_set_tsconfig_validate(struct ethnl_req_info *req_base,
-				       struct genl_info *info)
-{
-	const struct net_device_ops *ops = req_base->dev->netdev_ops;
-
-	if (!ops->ndo_hwtstamp_set || !ops->ndo_hwtstamp_get)
-		return -EOPNOTSUPP;
-
-	return 1;
-}
-
 static struct hwtstamp_provider *
 tsconfig_set_hwprov_from_desc(struct net_device *dev,
 			      struct genl_info *info,
@@ -459,6 +445,5 @@ const struct ethnl_request_ops ethnl_tsconfig_request_ops = {
 	.reply_size		= tsconfig_reply_size,
 	.fill_reply		= tsconfig_fill_reply,
 
-	.set_validate		= ethnl_set_tsconfig_validate,
 	.set			= ethnl_set_tsconfig,
 };

base-commit: f0b88fade64c6fe52e15b246097d10bb115d8af3
-- 
2.53.0