[Intel-wired-lan] [net-next v3 7/7] renesas: reject unsupported external timestamp flags

[Jacob Keller]

Fix the renesas PTP support to explicitly reject any future flags that
get added to the external timestamp request ioctl.

In order to maintain currently functioning code, this patch accepts all
three current flags. This is because the PTP_RISING_EDGE and
PTP_FALLING_EDGE flags have unclear semantics and each driver seems to
have interpreted them slightly differently.

Cc: Sergei Shtylyov <sergei.shtylyov at cogentembedded.com>
Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
---
 drivers/net/ethernet/renesas/ravb_ptp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/renesas/ravb_ptp.c b/drivers/net/ethernet/renesas/ravb_ptp.c
index 638f1fc2166f..666dbee48097 100644
--- a/drivers/net/ethernet/renesas/ravb_ptp.c
+++ b/drivers/net/ethernet/renesas/ravb_ptp.c
@@ -182,6 +182,12 @@ static int ravb_ptp_extts(struct ptp_clock_info *ptp,
 	struct net_device *ndev = priv->ndev;
 	unsigned long flags;
 
+	/* Reject requests with unsupported flags */
+	if (req->flags & ~(PTP_ENABLE_FEATURE |
+			   PTP_RISING_EDGE |
+			   PTP_FALLING_EDGE))
+		return -EOPNOTSUPP;
+
 	if (req->index)
 		return -EINVAL;
 
-- 
2.23.0.245.gf157bbb9169d