Re: [dpdk-dev] [PATCH v3 1/3] drivers/bus: move driver assignment to end of probing

[Thomas Monjalon <thomas@monjalon.net>]

11/10/2018 13:54, Andrew Rybchenko:
> On 10/11/18 2:45 PM, Thomas Monjalon wrote:
> > 11/10/2018 12:53, Andrew Rybchenko:
> >> On 10/8/18 1:09 AM, Thomas Monjalon wrote:
> >>> The PCI mapping requires to know the PCI driver to use,
> >>> even before the probing is done. That's why the PCI driver is
> >>> referenced early inside the PCI device structure. See
> >>> 1d20a073fa5e ("bus/pci: reference driver structure before mapping")
> >>>
> >>> However the rte_driver does not need to be referenced in rte_device
> >>> before the device probing is done.
> >>> By moving back this assignment at the end of the device probing,
> >>> it becomes possible to make clear the status of a rte_device.
> >>>
> >>> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> >>> ---
> >>> diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
> >>> index c7695d108..d63e68045 100644
> >>> --- a/drivers/bus/pci/pci_common.c
> >>> +++ b/drivers/bus/pci/pci_common.c
> >>> @@ -160,14 +160,12 @@ rte_pci_probe_one_driver(struct rte_pci_driver *dr,
> >>>    	 * driver flags for adjusting configuration.
> >>>    	 */
> >>>    	dev->driver = dr;
> >>> -	dev->device.driver = &dr->driver;
> >> It breaks net/sfc and I guess other drivers which use
> >> rte_eth_dma_zone_reserve()
> >> from probe. The function makes zone name using dev->device->driver->name.
> > Please, can you show code line where we does such access?
> >
> > I checked such access before and did not find some.
> > Anyway, it can be fixed by accessing rte_pci_driver->driver->name.
> > Note that rte_pci_driver is referenced in rte_pci_device.
> 
> Below in snprintf(), in theory it can be called for vdev as well.
> 
> const struct rte_memzone *
> rte_eth_dma_zone_reserve(const struct rte_eth_dev *dev, const char 
> *ring_name,
>                           uint16_t queue_id, size_t size, unsigned align,
>                           int socket_id)
> {
>          char z_name[RTE_MEMZONE_NAMESIZE];
>          const struct rte_memzone *mz;
> 
>          snprintf(z_name, sizeof(z_name), "%s_%s_%d_%d",
>                   dev->device->driver->name, ring_name,
>                   dev->data->port_id, queue_id);

I see, I missed it.

I think it's strange to use rte_device name for ethdev memory.
Should we use the ethdev name instead?

        snprintf(z_name, sizeof(z_name), "%s_%s_%d_%d",
-                dev->device->driver->name, ring_name,
+                dev->data->name, ring_name,
                 dev->data->port_id, queue_id);