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Date:   Wed, 4 Jan 2023 12:24:31 +0100
From:   Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
To:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Taku Izumi <izumi.taku@jp.fujitsu.com>,
        linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
        netdev@vger.kernel.org
Subject: Re: [PATCH net] fjes: Fix an error handling path in fjes_probe()
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References: <fde673f106d2b264ad76759195901aae94691b5c.1671569785.git.christophe.jaillet@wanadoo.fr>
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On Thu, Dec 29, 2022 at 05:34:22PM +0100, Christophe JAILLET wrote:
> Le 21/12/2022 ? 10:59, Michal Swiatkowski a ?crit?:
> > On Tue, Dec 20, 2022 at 09:57:06PM +0100, Christophe JAILLET wrote:
> > > A netif_napi_add() call is hidden in fjes_sw_init(). It should be undone
> > > by a corresponding netif_napi_del() call in the error handling path of the
> > > probe, as already done inthe remove function.
> > > 
> > > Fixes: 265859309a76 ("fjes: NAPI polling function")
> > > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > > ---
> > >   drivers/net/fjes/fjes_main.c | 4 +++-
> > >   1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/net/fjes/fjes_main.c b/drivers/net/fjes/fjes_main.c
> > > index 2513be6d4e11..01b4c9c6adbd 100644
> > > --- a/drivers/net/fjes/fjes_main.c
> > > +++ b/drivers/net/fjes/fjes_main.c
> > > @@ -1370,7 +1370,7 @@ static int fjes_probe(struct platform_device *plat_dev)
> > >   	adapter->txrx_wq = alloc_workqueue(DRV_NAME "/txrx", WQ_MEM_RECLAIM, 0);
> > >   	if (unlikely(!adapter->txrx_wq)) {
> > >   		err = -ENOMEM;
> > > -		goto err_free_netdev;
> > > +		goto err_del_napi;
> > >   	}
> > >   	adapter->control_wq = alloc_workqueue(DRV_NAME "/control",
> > > @@ -1431,6 +1431,8 @@ static int fjes_probe(struct platform_device *plat_dev)
> > >   	destroy_workqueue(adapter->control_wq);
> > >   err_free_txrx_wq:
> > >   	destroy_workqueue(adapter->txrx_wq);
> > > +err_del_napi:
> > > +	netif_napi_del(&adapter->napi);
> > >   err_free_netdev:
> > >   	free_netdev(netdev);
> > >   err_out:
> > 
> > Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
> > 
> > I wonder if it won't be better to have fjes_sw_deinit() instead or
> > change fjes_sw_init to only netif_napi_add(). You know, to avoid another
> > bug here when someone add sth to the fjes_sw_deinit(). This is only
> > suggestion, patch looks fine.
> 
> hi,
> 
> based on Jakub's comment [1], free_netdev() already cleans up NAPIs (see
> [2]).
> 
> So would it make more sense to remove netif_napi_del() from the .remove()
> function instead?
> The call looks useless to me now.
> 
> CJ
> 
> [1]: https://lore.kernel.org/all/20221221174043.1191996a@kernel.org/
> [2]: https://elixir.bootlin.com/linux/v6.2-rc1/source/net/core/dev.c#L10710
> 

Yeah, it make more sense.

Thanks, Michal
> > 
> > > -- 
> > > 2.34.1
> > > 
> > 
>