Re: [PATCH v2 2/4] ethdev: add siblings iterators

[Thomas Monjalon <thomas@monjalon.net>]

27/02/2019 11:51, Thomas Monjalon:
> 27/02/2019 11:07, Gaëtan Rivet:
> > On Wed, Feb 20, 2019 at 11:10:49PM +0100, Thomas Monjalon wrote:
> > > +uint16_t __rte_experimental
> > > +rte_eth_find_next_of(uint16_t port_id, const struct rte_device *parent)
> > > +{
> > > +	while (port_id < RTE_MAX_ETHPORTS &&
> > > +			rte_eth_devices[port_id].state == RTE_ETH_DEV_UNUSED &&
> > > +			rte_eth_devices[port_id].device != parent)
> > > +		port_id++;
> > 
> > Why not call rte_eth_find_next directly from this function, and
> > add your specific test on top of it?
> > 
> > Something like:
> > 
> >     	while (port_id < RTE_MAX_ETHPORTS &&
> >     	       rte_eth_devices[port_id].device != parent)
> >     		port_id = rte_eth_find_next(port_id + 1);
> > 
> > this way you won't have to rewrite the test on the device state. Having the
> > logic expressed in several places would make reworking the device states more
> > complicated than necessary if it were to happen (just as you did when switching
> > the test from !(ATTACHED || REMOVED) to (UNUSED).
> 
> About the intent, you are right.
> About the solution, it seems buggy. We can try to find another way
> of coding this loop by using rte_eth_find_next()
> and adding the parent condition.

Your proposal is correct if adding a first call before the loop:
	port_id = rte_eth_find_next(port_id);