Re: [PATCH for-next v2] IB/core: Add more speed parsing in ib_get_width_and_speed()

[Leon Romanovsky <leon@kernel.org>]

On Fri, Aug 04, 2023 at 09:43:28AM +0530, Selvin Xavier wrote:
> On Thu, Aug 3, 2023 at 11:28 PM Leon Romanovsky <leon@kernel.org> wrote:
> >
> > On Wed, Aug 02, 2023 at 02:00:23AM -0700, Selvin Xavier wrote:
> > > From: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> > >
> > > When the Ethernet driver does not provide the number of lanes
> > > in the __ethtool_get_link_ksettings() response, the function
> > > ib_get_width_and_speed() does not take consideration of 50G,
> > > 100G and 200G speeds while calculating the IB width and speed.
> > > Update the width and speed for the above netdev speeds.
> > >
> > > Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
> > > Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
> > > ---
> > > v1 - v2:
> > >     - Rebased the patch based on the latest changes in ib_get_width_and_speed
> > >     - removed the switch case and use the existing else if check
> > > ---
> > >  drivers/infiniband/core/verbs.c | 11 ++++++++++-
> > >  1 file changed, 10 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
> > > index 25367bd..41ff559 100644
> > > --- a/drivers/infiniband/core/verbs.c
> > > +++ b/drivers/infiniband/core/verbs.c
> > > @@ -1899,9 +1899,18 @@ static void ib_get_width_and_speed(u32 netdev_speed, u32 lanes,
> > >               } else if (netdev_speed <= SPEED_40000) {
> > >                       *width = IB_WIDTH_4X;
> > >                       *speed = IB_SPEED_FDR10;
> > > -             } else {
> > > +             } else if (netdev_speed <= SPEED_50000) {
> > > +                     *width = IB_WIDTH_2X;
> > > +                     *speed = IB_SPEED_EDR;
> > > +             } else if (netdev_speed <= SPEED_100000) {
> > >                       *width = IB_WIDTH_4X;
> > >                       *speed = IB_SPEED_EDR;
> > > +             } else if (netdev_speed <= SPEED_200000) {
> > > +                     *width = IB_WIDTH_4X;
> > > +                     *speed = IB_SPEED_HDR;
> >
> >
> > SPEED_50000, SPEED_100000 and SPEED_200000 depends on
> > ClassPortInfo:CapabilityMask2.is* values.
> >
> > For example, SPEED_50000 can b IB_WIDTH_2X/IB_SPEED_EDR and IB_WIDTH_1X/IB_SPEED_HDR.
> Agree with that.
> This reporting can be achieved by the existing code, but the L2 driver
> needs to report non zero values for lanes in
> ethtool_ops->get_link_ksettings.
> Caller of this modified function gets the speed and number of lanes
> from ethtool_ops->get_link_ksettings.
> 
> In this patch we are trying to handle the case where ethtool ops
> doesn't provide the lanes.  

Almost all drivers don't support lanes reporting.

> We can  default to some value so that we
> dont report wrong total link speed (width * speed) for any speed more
> than 40G.
> >
> > Thanks
> >
> > > +             } else {
> > > +                     *width = IB_WIDTH_4X;
> > > +                     *speed = IB_SPEED_NDR;
> > >               }
> > >
> > >               return;
> > > --
> > > 2.5.5
> > >
> >
> >