[Intel-wired-lan] [PATCH iwl-net] ice: fix incorrect PHY settings for 100 GB/s

[Korba, Przemyslaw]

> 
> Dear Przemyslaw,
> 
> 
> 
> Thank you for your patch.
> 
> Am 26.11.24 um 11:23 schrieb Przemyslaw Korba:
> > ptp4l application reports too high offset when ran on E823 device with
> > a 100GB/s link. Those values cannot go under 100ns, like in a PTP
> > working case when using 100 GB/s cable.
> > This is due to incorrect frequency settings on the PHY clocks for
> > 100 GB/s speed. Changes are introduced to align with the internal
> > hardware documentation, and correctly initialize frequency in PHY
> 
> It’d be great if you added the documentation name.

I don't think I can, this is Intel's restricted secret document
 
> 
> > clocks with the frequency values that are in our HW spec.
> > To reproduce the issue run ptp4l as a Time Receiver on E823 device,
> > and observe the offset, which will never approach values seen in the
> > PTP working case.
> 
> (I’d add a blank line between paragraphs.)

Good point, will do.

> 
> Also, I always like to see pastes from the commands you ran to reproduce this. It’s
> always good for comparison.

Sure, will attach once window is opened.

> 
> > Fixes: 3a7496234d17 ("ice: implement basic E822 PTP support")
> 
> Any idea, where the wrong values came from? Will your test be added to the test
> procedure?

Wrong values come from incorrect vernier calculations. I will attach the ptp4l
logs to commit message once window is opened. We should have additional 
validation case for it in the near future. Thanks for reviewing! : )

> 
> > Reviewed-by: Milena Olech <milena.olech at intel.com>
> > Signed-off-by: Przemyslaw Korba <przemyslaw.korba at intel.com>
> > ---
> >   drivers/net/ethernet/intel/ice/ice_ptp_consts.h | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_consts.h
> > b/drivers/net/ethernet/intel/ice/ice_ptp_consts.h
> > index 6620642077bb..bdb1020147d1 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_ptp_consts.h
> > +++ b/drivers/net/ethernet/intel/ice/ice_ptp_consts.h
> > @@ -761,9 +761,9 @@ const struct ice_vernier_info_e82x
> e822_vernier[NUM_ICE_PTP_LNK_SPD] = {
> >   		/* rx_desk_rsgb_par */
> >   		644531250, /* 644.53125 MHz Reed Solomon gearbox */
> >   		/* tx_desk_rsgb_pcs */
> > -		644531250, /* 644.53125 MHz Reed Solomon gearbox */
> > +		390625000, /* 390.625 MHz Reed Solomon gearbox */
> >   		/* rx_desk_rsgb_pcs */
> > -		644531250, /* 644.53125 MHz Reed Solomon gearbox */
> > +		390625000, /* 390.625 MHz Reed Solomon gearbox */
> >   		/* tx_fixed_delay */
> >   		1620,
> >   		/* pmd_adj_divisor */
> 
> Kind regards,
> 
> Paul