Re: [PATCH net-next v7 15/16] net: ethtool: ts: Let the active time stamping layer be selectable

[Köry Maincent]

On Sat, 18 Nov 2023 18:34:33 -0800
Jakub Kicinski <kuba@xxxxxxxxxx> wrote:

> On Tue, 14 Nov 2023 12:28:43 +0100 Kory Maincent wrote:
> > +	if (!tb[ETHTOOL_A_TS_LAYER])
> > +		return 0;  
> 
> GENL_REQ_ATTR_CHECK(), not sure why anyone would issue this command
> without any useful attr.
> 
> > +	/* Disable time stamping in the current layer. */
> > +	if (netif_device_present(dev) &&
> > +	    (dev->ts_layer == PHY_TIMESTAMPING ||
> > +	    dev->ts_layer == MAC_TIMESTAMPING)) {
> > +		ret = dev_set_hwtstamp_phylib(dev, &config, info->extack);
> > +		if (ret < 0)
> > +			return ret;  
> 
> So you only support PHYLIB?
> 
> The semantics need to be better documented :(

Yes as we don't really know how each MAC deal with the timestamping
before ndo_hwstamp_get/set. Using phylib only allows us to be sure these NDO are
implemented and the management of timestamping is coherent in the MAC. Also It
will push people to move on to these NDOs.

Ok I will add documentation.

-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com