Subject: Re: [PATCH] vdpa/mlx5: Extract correct pointer from driver data

From: Leon Romanovsky <[email-masked]>
Date: Tue, 16 Feb 2021 15:17:44 +0200

On Tue, Feb 16, 2021 at 02:45:40PM +0200, Eli Cohen wrote:
> On Tue, Feb 16, 2021 at 09:37:34AM +0200, Leon Romanovsky wrote:
> > On Tue, Feb 16, 2021 at 08:42:26AM +0200, Eli Cohen wrote:
> > > On Tue, Feb 16, 2021 at 08:35:51AM +0200, Leon Romanovsky wrote:
> > > > On Tue, Feb 16, 2021 at 07:50:22AM +0200, Eli Cohen wrote:
> > > > > struct mlx5_vdpa_net pointer was stored in drvdata. Extract it as well
> > > > > in mlx5v_remove().
> > > > >
> > > > > Fixes: 74c9729dd892 ("vdpa/mlx5: Connect mlx5_vdpa to auxiliary bus")
> > > > > Signed-off-by: Eli Cohen <[email-masked]>
> > > > > ---
> > > > >  drivers/vdpa/mlx5/net/mlx5_vnet.c | 4 ++--
> > > > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > index 6b0a42183622..4103d3b64a2a 100644
> > > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > > > > @@ -2036,9 +2036,9 @@ static int mlx5v_probe(struct auxiliary_device *adev,
> > > > >
> > > > >  static void mlx5v_remove(struct auxiliary_device *adev)
> > > > >  {
> > > > > -	struct mlx5_vdpa_dev *mvdev = dev_get_drvdata(&adev->dev);
> > > > > +	struct mlx5_vdpa_net *ndev = dev_get_drvdata(&adev->dev);
> > > > >
> > > > > -	vdpa_unregister_device(&mvdev->vdev);
> > > > > +	vdpa_unregister_device(&ndev->mvdev.vdev);
> > > > >  }
> > > >
> > > > IMHO, The more correct solution is to fix dev_set_drvdata() call,
> > > > because we are regustering/unregistering/allocating "struct mlx5_vdpa_dev".
> > > >
> > >
> > > We're allocating "struct mlx5_vdpa_net". "struct mlx5_vdpa_dev" is just
> > > a member field of "struct mlx5_vdpa_net".
> >
> > I referred to these lines in the mlx5v_probe():
> >   1986         err = mlx5_vdpa_alloc_resources(&ndev->mvdev);
> >   1987         if (err)
> >   1988                 goto err_mtu;
> >   1989
> >   1990         err = alloc_resources(ndev);
> >   1991         if (err)
> >   1992                 goto err_res;
> >   1993
> >   1994         err = vdpa_register_device(&mvdev->vdev);
> >
> > So mlx5v_remove() is better to be symmetrical.
> >
>
> It's "struct mlx5_vdpa_net" that is being allocated here so it makes
> sense to set this pointer as the the driver data.

Anyway, it doesn't important.

Thanks, for the original patch.
Reviewed-by: Leon Romanovsky <[email-masked]>