On Thu, May 11, 2023 at 6:32 AM Vladimir Oltean [off-list ref] wrote:

On Mon, May 01, 2023 at 10:31:46PM -0600, Maxim Georgiev wrote:

quoted

 struct net_device_ops {
      int                     (*ndo_init)(struct net_device *dev);

@@ -1649,6 +1659,12 @@ struct net_device_ops {
      ktime_t                 (*ndo_get_tstamp)(struct net_device *dev,
                                                const struct skb_shared_hwtstamps *hwtstamps,
                                                bool cycles);
+     int                     (*ndo_hwtstamp_get)(struct net_device *dev,
+                                                 struct kernel_hwtstamp_config *kernel_config,
+                                                 struct netlink_ext_ack *extack);

I'm not sure it is necessary to pass an extack to "get". That should
only give a more detailed reason if the driver refuses something.

I have to admit I just followed Jakub's guidance adding "extack" to the
list of parametres. I'll let Jakub to comment on that.

For that matter, now that ndo_hwtstamp_get() should no longer be
concerned with the copy_to_user(), I'm not even sure that it should
return int at all, and not void. The transition is going to be slightly
problematic though, with the generic_hwtstamp_get_lower() necessarily
still calling dev_eth_ioctl() -> copy_to_user(), so we probably can't
make it void just now.

Would it make sense to keep the return int value here "for future extensions"?