[PATCH net-next 2/2] net: stmmac: intel: only populate plat->crosststamp when supported

["Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>]

To allow the ptp_chardev code to correctly detect whether crosststamps
are supported, we need to conditionally populate the .getcrosststamp()
method. As the previous patch implements that functionality by
detecting whether the platform glue provides a crosststamp() method,
arrange for the dwmac-intel code to only populate this if the X86
ART feature is present, rather than testing for it at runtime in
intel_crosststamp().

This reflects what other x86 PTP clock drivers do, e.g.
ice_ptp_set_funcs_e830(), e1000e_ptp_init(), idpf_ptp_set_caps() etc.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
index d900b93f46ce..e74d00984b88 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
@@ -371,9 +371,6 @@ static int intel_crosststamp(ktime_t *device,
 	u32 acr_value;
 	int i;
 
-	if (!boot_cpu_has(X86_FEATURE_ART))
-		return -EOPNOTSUPP;
-
 	intel_priv = priv->plat->bsp_priv;
 
 	/* Both internal crosstimestamping and external triggered event
@@ -756,7 +753,9 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 
 	plat->int_snapshot_num = AUX_SNAPSHOT1;
 
-	plat->crosststamp = intel_crosststamp;
+	if (boot_cpu_has(X86_FEATURE_ART))
+		plat->crosststamp = intel_crosststamp;
+
 	plat->flags &= ~STMMAC_FLAG_INT_SNAPSHOT_EN;
 
 	/* Setup MSI vector offset specific to Intel mGbE controller */
-- 
2.47.2