Re: [PATCH net-next v19 09/10] net: ethtool: Add support for tsconfig command to get/set hwtstamp config

[Kory Maincent <kory.maincent@bootlin.com>]

On Sat, 9 Nov 2024 01:43:30 +0000
Vadim Fedorenko <vadim.fedorenko@linux.dev> wrote:

> > +	ret = net_hwtstamp_validate(&hwtst_config);
> > +	if (ret)
> > +		goto err_clock_put;
> > +
> > +	if (mod) {
> > +		struct kernel_hwtstamp_config zero_config = {0};
> > +		struct hwtstamp_provider *__hwtstamp;
> > +
> > +		/* Disable current time stamping if we try to enable
> > +		 * another one
> > +		 */
> > +		ret = dev_set_hwtstamp_phylib(dev, &zero_config,
> > info->extack);  
> 		
> _hwtst_config is still inited to 0 here, maybe it can be used to avoid
> another stack allocation?

You are right, thanks!

> 
> > +		if (ret < 0)
> > +			goto err_clock_put;
> > +
> > +		/* Change the selected hwtstamp source */
> > +		__hwtstamp = rcu_replace_pointer_rtnl(dev->hwtstamp,
> > hwtstamp);
> > +		if (__hwtstamp)
> > +			call_rcu(&__hwtstamp->rcu_head,
> > +				 remove_hwtstamp_provider);
> > +	} else {
> > +		/* Get current hwtstamp config if we are not changing the
> > +		 * hwtstamp source
> > +		 */
> > +		ret = dev_get_hwtstamp_phylib(dev, &_hwtst_config);  
> 
> This may be tricky whithout ifr set properly. But it should force
> drivers to be converted.

It is the point, it even return not supported error if ndo_hwtstamp_set/get are
not defined.
 
> > +		if (ret < 0 && ret != -EOPNOTSUPP)
> > +			goto err_clock_put;
> > +	}
> > +
> > +	if (memcmp(&hwtst_config, &_hwtst_config, sizeof(hwtst_config))) {
> >  
> 
> better to use kernel_hwtstamp_config_changed() helper here

Oh yes, thanks for pointing it out.

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