On 06/05/20 12:48 +0100, Ferruh Yigit wrote:
> On 5/5/2020 8:10 PM, Gaetan Rivet wrote:
> > When a net_ring device is allocated, its device pointer is not set
> > before calling rte_eth_dev_probing_finish, which is incorrect.
> >
> > The following:
> > commit: 96cb19521147 ("net/ring: use EAL APIs in PMD specific API")
> > commit: a6992e961050 ("net/ring: set ethernet device field")
> >
> > already attempted to fix this issue in 17.08, which was fine at the
> > time. Adding the hook rte_eth_dev_probing_finish() however created this
> > bug, as the eth_dev exposed when this hook is executed is expected to be
> > complete.
> >
> > Remove the prior attempts to fix the issue in rte_pmd_ring_probe() and
> > write the pointer properly in do_eth_dev_ring_create().
> >
> > Cc: sta...@dpdk.org
> > Fixes: fbe90cdd776c ("ethdev: add probing finish function")
> > Cc: ferruh.yi...@intel.com
> > Cc: tho...@monjalon.net
> > Signed-off-by: Gaetan Rivet <gr...@u256.net>
>
> <...>
>
> > @@ -325,10 +346,17 @@ do_eth_dev_ring_create(const char *name,
> > data->kdrv = RTE_KDRV_NONE;
> > data->numa_node = numa_node;
> >
> > - /* finally assign rx and tx ops */
> > + /* assign rx and tx ops */
> > eth_dev->rx_pkt_burst = eth_ring_rx;
> > eth_dev->tx_pkt_burst = eth_ring_tx;
> >
> > + /* finally set the rte_device pointer in eth_dev. */
> > + eth_dev->device = ring_device_from_name(name);
> > + if (eth_dev->device == NULL) {
> > + rte_errno = ENODEV;
> > + goto error;
> > + }
> > +
> > rte_eth_dev_probing_finish(eth_dev);
> > *eth_dev_p = eth_dev;
>
> Why not move the 'rte_eth_dev_probing_finish()' to the 'rte_pmd_ring_probe()',
> below where 'eth_dev->device' set?
Hi Ferruh,
Sure it would work. The reason I did it this way is two-fold:
* I disliked having two places where eth_dev->device was conditionally
set. It makes it harder to read rte_pmd_ring_probe.
* I was actually thinking, doing this patch, that we should modify
rte_eth_dev_allocate() to take an rte_device as parameter, as all
eth_dev are meant to be backed by an rte_device. Keeping this in
mind, I meant to move writing the pointer closer to the
rte_eth_dev_allocate() call.
But you are right that it is needlessly verbose, using
vdev_bus->find_device() to do this stuff. I'm ok with changing it as you
described if you prefer.
--
Gaëtan
