On Sun, Aug 20, 2023 at 12:59:26PM +0300, Leon Romanovsky wrote:
> On Fri, Aug 18, 2023 at 01:42:30PM -0300, Jason Gunthorpe wrote:
> > On Fri, Aug 18, 2023 at 01:33:35PM -0300, Jason Gunthorpe wrote:
> > > On Wed, Aug 16, 2023 at 09:52:23AM +0300, Leon Romanovsky wrote:
> > > > From: Mark Bloch <mbloch@xxxxxxxxxx>
> > > >
> > > > If the RDMA device isn't in LAG mode there is no need
> > > > to try to get the upper device.
> > > >
> > > > Signed-off-by: Mark Bloch <mbloch@xxxxxxxxxx>
> > > > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
> > > > ---
> > > > drivers/infiniband/hw/mlx5/main.c | 22 +++++++++++++++-------
> > > > 1 file changed, 15 insertions(+), 7 deletions(-)
> > > >
> > > > diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
> > > > index f0b394ed7452..215d7b0add8f 100644
> > > > --- a/drivers/infiniband/hw/mlx5/main.c
> > > > +++ b/drivers/infiniband/hw/mlx5/main.c
> > > > @@ -195,12 +195,18 @@ static int mlx5_netdev_event(struct notifier_block *this,
> > > > case NETDEV_CHANGE:
> > > > case NETDEV_UP:
> > > > case NETDEV_DOWN: {
> > > > - struct net_device *lag_ndev = mlx5_lag_get_roce_netdev(mdev);
> > > > struct net_device *upper = NULL;
> > > >
> > > > - if (lag_ndev) {
> > > > - upper = netdev_master_upper_dev_get(lag_ndev);
> > > > - dev_put(lag_ndev);
> > > > + if (ibdev->lag_active) {
> > >
> > > Needs locking to read lag_active
> >
> > Specifically the use of the bitfield looks messed up.. If lag_active
> > and some others were set only during probe it could be OK.
>
> All fields except ib_active are static and set during probe.
>
> >
> > But mixing other stuff that is being written concurrently is not OK to
> > do like this. (eg ib_active via a mlx5 notifier)
>
> What you are looking is the following change, did I get you right?
>
> diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> index 9d0c56b59ed2..ee73113717b2 100644
> --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
> +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> @@ -1094,7 +1094,7 @@ struct mlx5_ib_dev {
> /* serialize update of capability mask
> */
> struct mutex cap_mask_mutex;
> - u8 ib_active:1;
> + bool ib_active;
> u8 is_rep:1;
> u8 lag_active:1;
> u8 wc_support:1;
That helps, but it still needs some kind of concurrency management for
ib_active
Jason
