Re: [dpdk-dev] [PATCH v4 3/3] ethdev: allow close function to return an error

[Thomas Monjalon <thomas@monjalon.net>]

06/10/2020 11:43, Ferruh Yigit:
> On 10/5/2020 6:08 PM, Thomas Monjalon wrote:
> > The API function rte_eth_dev_close() was returning void.
> > The return type is changed to int for notifying of errors.
> > 
> > If an error happens during a close operation,
> > the status of the port is undefined,
> > a maximum of resources having been freed.
> > 
> > Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> > Reviewed-by: Liron Himi <lironh@marvell.com>
> > Acked-by: Stephen Hemminger <stephen@networkplumber.org>
> 
> <...>
> 
> > -void
> > +int
> >   rte_eth_dev_close(uint16_t port_id)
> >   {
> >   	struct rte_eth_dev *dev;
> > +	int firsterr, binerr;
> > +	int *lasterr = &firsterr;
> >   
> > -	RTE_ETH_VALID_PORTID_OR_RET(port_id);
> > +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
> >   	dev = &rte_eth_devices[port_id];
> >   
> > -	RTE_FUNC_PTR_OR_RET(*dev->dev_ops->dev_close);
> > -	(*dev->dev_ops->dev_close)(dev);
> > +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_close, -ENOTSUP);
> > +	*lasterr = (*dev->dev_ops->dev_close)(dev);
> > +	if (*lasterr != 0)
> > +		lasterr = &binerr;
> >   
> >   	rte_ethdev_trace_close(port_id);
> > -	rte_eth_dev_release_port(dev);
> > +	*lasterr = rte_eth_dev_release_port(dev);
> > +
> > +	return firsterr;
> >   }
> 
> This may be personal taste but above error handling looks like unnecessary 
> complex, what do you think something like below:
> 
> close_err = (*dev->dev_ops->dev_close)(dev);
> release_err = rte_eth_dev_release_port(dev);
> return close_err ? close_err : release_err;

This is what I did first. Then thought about this "elegant" handling.
The pointer solution is just one more line and is more future proof.

I'm fine with any choice. Andrew?