24/08/2017 09:12, Shahaf Shuler:
> Thursday, August 24, 2017 1:06 AM, Thomas Monjalon:
> > 23/08/2017 15:13, Shahaf Shuler:
> > > Wednesday, August 23, 2017 3:29 PM, Ananyev, Konstantin:
> > > > From: Shahaf Shuler
> > > > > In order to enable PMDs to support only one of the APIs, and
> > > > > applications to avoid branching according to the underlying device
> > > > > a copy functions to/from the old/new APIs were added.
> >
> > Looks a good intent.
> > I would prefer the word "convert" instead of "copy".
> >
> > > > > int
> > > > > rte_eth_rx_queue_setup(uint8_t port_id, uint16_t rx_queue_id,
> > [...]
> > > > > + } else if ((!(dev->data->dev_flags & RTE_ETH_DEV_RXQ_OFFLOAD))
> > > > > &&
> > > > > + (dev->data->dev_conf.rxmode.ignore == 1)) {
> > > > > + int ret;
> > > > > + struct rte_eth_rxmode rxmode;
> > > > > +
> > > > > + rte_eth_copy_rxq_offloads(&rxmode, rx_conf);
> > > > > + if (memcmp(&rxmode, &dev->data->dev_conf.rxmode,
> > > > > + sizeof(rxmode))) {
> > > > > + /*
> > > > > + * device which work with rxmode offloads API
> > > > > requires
> > > > > + * a re-configuration in order to apply the new
> > > > > offloads
> > > > > + * configuration.
> > > > > + */
> > > > > + dev->data->dev_conf.rxmode = rxmode;
> > > > > + ret = rte_eth_dev_configure(port_id,
> > > > > + dev->data->nb_rx_queues,
> > > > > + dev->data->nb_tx_queues,
> > > > > + &dev->data->dev_conf);
> > > >
> > > > Hmm, and why we would need to reconfigure our device in the middle
> > > > of rx queue setup?
> > >
> > > The reason is the old Rx offloads API is configured on device configure.
> > > This if section is for applications which already moved to the new
> > > offload API however the underlying PMD still uses the old one.
> >
> > Isn't it risky to re-run configure here?
> > We could also declare this case as an error.
> >
> > I think applications which have migrated to the new API, could use the
> > convert functions themselves before calling configure to support not
> > migrated PMDs.
> > The cons of my solution are:
> > - discourage apps to migrate before all PMDs have migrated
> > - expose a temporary function to convert API I propose it anyway because
> > there is always someone to like bad ideas ;)
>
> Yes. I tried to make it as simple as possible for application to move to the
> new API.
> Defining it as error flow, will enforce the application to check the PMD
> offload mode and branch accordingly. The conversion functions are a good
> helpers, yet the code remains complex due to the different cases with the
> different PMDs.
>
> Considering the re-configuration is risky, and without other ideas I will
> need to fall back to the error flow case.
> Are we OK with that?
I think we can take the risk of keeping this call to
rte_eth_dev_configure() in the middle of rte_eth_rx_queue_setup().
In theory it should be acceptable.
If we merge it soon, it can be better tested with every drivers.
