Re: [PATCH net 0/3] Fix bugs in Octeontx2 netdev driver

From: sundeep subbaraya <sundeep.lkml@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>,
	netdev@vger.kernel.org, sgoutham@marvell.com,
	Subbaraya Sundeep <sbhatta@marvell.com>
Subject: Re: [PATCH net 0/3] Fix bugs in Octeontx2 netdev driver
Date: Fri, 24 Jul 2020 08:40:44 +0530	[thread overview]
Message-ID: <CALHRZupBXQqOzWhNH=qDH7w1cNLYrEWLTwt368sBJt4FiJTBWQ@mail.gmail.com> (raw)
In-Reply-To: <20200723.121345.1943051054532406842.davem@davemloft.net>

Hi David,

On Fri, Jul 24, 2020 at 12:43 AM David Miller <davem@davemloft.net> wrote:
>
> From: sundeep subbaraya <sundeep.lkml@gmail.com>
> Date: Thu, 23 Jul 2020 20:29:03 +0530
>
> > Hi David,
> >
> > On Wed, Jul 22, 2020 at 7:34 PM sundeep subbaraya
> > <sundeep.lkml@gmail.com> wrote:
> >>
> >> Hi David,
> >>
> >> On Wed, Jul 22, 2020 at 4:47 AM David Miller <davem@davemloft.net> wrote:
> >> >
> >> > From: sundeep.lkml@gmail.com
> >> > Date: Tue, 21 Jul 2020 22:44:05 +0530
> >> >
> >> > > Subbaraya Sundeep (3):
> >> > >   octeontx2-pf: Fix reset_task bugs
> >> > >   octeontx2-pf: cancel reset_task work
> >> > >   octeontx2-pf: Unregister netdev at driver remove
> >> >
> >> > I think you should shut down all the interrupts and other state
> >> > before unregistering the vf network device.
> >>
> >> Okay will change it and send v2.
> >>
> >
> > For our case interrupts need to be ON when unregister_netdev is called.
> > If driver remove is called when the interface is up then
> > otx2_stop(called by unregister_netdev)
> > needs mailbox interrupts to communicate with PF to release its resources.
>
> If you leave interrupts on then an interrupt can arrive after the software
> state has been released by unregister_netdev.
>
> Sounds like you need to resolve this some other way.

Only mailbox interrupts can arrive after unregister_netdev since
otx2_stop disables
the packet I/O and its interrupts as the first step.
And mbox interrupts are turned off after unregister_neetdev.
unregister_netdev(netdev);
otx2vf_disable_mbox_intr(vf);

Thanks,
Sundeep