From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Iremonger, Bernard" <bernard.iremonger@intel.com>
Subject: Re: [PATCH v3 1/4] app/testpmd: allow detaching a
	port	not closed
Date: Wed, 17 Oct 2018 10:30:25 +0000
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 <20181017015450.15783-2-thomas@monjalon.net>
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Cc: "Yigit, Ferruh" <ferruh.yigit@intel.com>, "dev@dpdk.org" <dev@dpdk.org>,
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To: Thomas Monjalon <thomas@monjalon.net>, Andrew Rybchenko
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Hi Thomas,

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Thomas Monjalon
> Sent: Wednesday, October 17, 2018 9:21 AM
> To: Andrew Rybchenko <arybchenko@solarflare.com>
> Cc: Yigit, Ferruh <ferruh.yigit@intel.com>; dev@dpdk.org;
> ophirmu@mellanox.com
> Subject: Re: [dpdk-dev] [PATCH v3 1/4] app/testpmd: allow detaching a por=
t not
> closed
>=20
> 17/10/2018 08:26, Andrew Rybchenko:
> > On 10/17/18 4:54 AM, Thomas Monjalon wrote:
> > > The testpmd application aim is for testing; so order of operations
> > > should not be enforced.
> > >
> > > There was a test to forbid detaching before closing a port.
> > > However, it may interesting to test what happens in such case.
> > > It is possible for a PMD to automatically close the port when detachi=
ng.
> > >
> > > Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> >
> > I'm afraid it could be a problem which the patch, since port close
> > ensures that the port is not used for traffic forwarding.
> > Right now the check is gone and we can detach port which is used for
> > traffic forwarding on separate data cores.
> > So, almost guaranteed crash.
>=20
> Yes I can duplicate this check in detach_port().

I agree with Andrew that this will cause a crash.

I don't understand why the sequence is changing here.
The close(), detach()  sequence has been in place since the port hot plug w=
ork some years ago, user applications may already be using this sequence.

Regards,

Bernard.

=20