Re: [dpdk-dev] [PATCH v5 1/3] ethdev: new API to free consumed buffers in Tx ring

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2017-03-09 10:49, Billy McFall:
> On Tue, Mar 7, 2017 at 11:03 AM, Thomas Monjalon <thomas.monjalon@6wind.com>
> wrote:
> > 2017-03-07 09:29, Billy McFall:
> > > On Mon, Feb 27, 2017 at 8:48 AM, Thomas Monjalon <
> > thomas.monjalon@6wind.com>
> > > wrote:
> > > > I think you could use rte_errno (while keeping negative return codes).
> > > >
> > >
> > > I can do that if you want, but if I understand your comment, it will make
> > > the implementation of the function not as clean. I cannot use the
> > existing
> > > RTE_ETH_VALID_PORTID_OR_ERR_RET(..) and RTE_FUNC_PTR_OR_ERR_RET(..)
> > MACROs
> > > because they are handling the return on error. Or am I missing something?
> >
> > Yes. Maybe we need new macros for basic error management with rte_errno.
> >
> > Looking at the code. Do you think we need new MACROs or just set rte_errno
> in the existing? What would be the down side to setting rte_errno for all
> the existing calls?
> 
> Looks like RTE_ETH_VALID_PORTID_OR_ERR_RET(..) is being called ~135 times.
> Most calls are with retval set to either -ENODEV or -EINVAL. A few
> instances of 0 and -1, but not many.
> 
> Looks like RTE_FUNC_PTR_OR_ERR_RET(..) is being called ~100 times. Most
> calls are with retval set to -ENOTSUP. A few instances of 0, but not many.
> 
> I was thinking:
> /* Macros to check for valid port */
> #define RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, retval) do { \
> if (!rte_eth_dev_is_valid_port(port_id)) { \
> RTE_PMD_DEBUG_TRACE("Invalid port_id=%d\n", port_id); \
> + if (retval < 0) \
> + rte_errno = -retval; \
> return retval; \
> } \
> } while (0)

Yes it seems acceptable.
This rework may be done separately.