Re: [PATCH] ethdev: fix push new event

[Thomas Monjalon <thomas@monjalon.net>]

23/05/2022 11:51, David Marchand:
> On Sat, May 21, 2022 at 8:57 AM Min Hu (Connor) <humin29@huawei.com> wrote:
> >
> > From: Huisong Li <lihuisong@huawei.com>
> >
> > The 'state' in struct rte_eth_dev may be used to update some information
> > when app receive these events. For example, when app receives a new event,
> > app may get the socket id of this port by calling rte_eth_dev_socket_id to
> > setup the attached port. The 'state' is used in rte_eth_dev_socket_id.
> >
> > If the state isn't modified to RTE_ETH_DEV_ATTACHED before pushing the new
> > event, app will get the socket id failed. So this patch moves pushing event
> > operation after the state updated.
> >
> > Fixes: 99a2dd955fba ("lib: remove librte_ prefix from directory names")
> 
> A patch moving code is unlikely to be at fault.
> 
> 
> Looking at the patch which moved those notifications in this point of
> the code, the state update was pushed after the notification on
> purpose.
> See be8cd210379a ("ethdev: fix port probing notification")
> 
>     ethdev: fix port probing notification
> 
>     The new device was notified as soon as it was allocated.
>     It leads to use a device which is not yet initialized.
> 
>     The notification must be published after the initialization is done
>     by the PMD, but before the state is changed, in order to let
>     notified entities taking ownership before general availability.
> 
> 
> Do we need an intermediate state during probing?

Possibly. Currently we have only 3 states:
	RTE_ETH_DEV_UNUSED
	RTE_ETH_DEV_ATTACHED
	RTE_ETH_DEV_REMOVED

We may add RTE_ETH_DEV_ALLOCATED just before calling
	rte_eth_dev_callback_process(dev, RTE_ETH_EVENT_NEW, NULL);
Then we would need to check against RTE_ETH_DEV_ALLOCATED
in some ethdev functions.