Re: [PATCH net-next v2 2/2] amd-xgbe: add support for rx-adaptation

[Simon Horman <simon.horman@corigine.com>]

On Fri, Feb 03, 2023 at 01:49:01PM +0530, Raju Rangoju wrote:
> 
> 
> On 2/3/2023 1:39 PM, Simon Horman wrote:
> > On Thu, Feb 02, 2023 at 03:16:50PM +0100, Paolo Abeni wrote:
> > > On Wed, 2023-02-01 at 18:11 +0100, Simon Horman wrote:
> > > > On Wed, Feb 01, 2023 at 11:19:32AM +0530, Raju Rangoju wrote:
> > > > > The existing implementation for non-Autonegotiation 10G speed modes does
> > > > > not enable RX adaptation in the Driver and FW. The RX Equalization
> > > > > settings (AFE settings alone) are manually configured and the existing
> > > > > link-up sequence in the driver does not perform rx adaptation process as
> > > > > mentioned in the Synopsys databook. There's a customer request for 10G
> > > > > backplane mode without Auto-negotiation and for the DAC cables of more
> > > > > significant length that follow the non-Autonegotiation mode. These modes
> > > > > require PHY to perform RX Adaptation.
> > > > > 
> > > > > The proposed logic adds the necessary changes to Yellow Carp devices to
> > > > > ensure seamless RX Adaptation for 10G-SFI (LONG DAC) and 10G-KR without
> > > > > AN (CL72 not present). The RX adaptation core algorithm is executed by
> > > > > firmware, however, to achieve that a new mailbox sub-command is required
> > > > > to be sent by the driver.
> > > > > 
> > > > > Co-developed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> > > > > Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> > > > > Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
> > > > 
> > > > ...
> > > > 
> > > > > diff --git a/drivers/net/ethernet/amd/xgbe/xgbe.h b/drivers/net/ethernet/amd/xgbe/xgbe.h
> > > > > index 16e73df3e9b9..ad136ed493ed 100644
> > > > > --- a/drivers/net/ethernet/amd/xgbe/xgbe.h
> > > > > +++ b/drivers/net/ethernet/amd/xgbe/xgbe.h
> > > > > @@ -625,6 +625,7 @@ enum xgbe_mb_cmd {
> > > > >   enum xgbe_mb_subcmd {
> > > > >   	XGBE_MB_SUBCMD_NONE = 0,
> > > > > +	XGBE_MB_SUBCMD_RX_ADAP,
> > > > >   	/* 10GbE SFP subcommands */
> > > > >   	XGBE_MB_SUBCMD_ACTIVE = 0,
> > > > > @@ -1316,6 +1317,10 @@ struct xgbe_prv_data {
> > > > >   	bool debugfs_an_cdr_workaround;
> > > > >   	bool debugfs_an_cdr_track_early;
> > > > > +	bool en_rx_adap;
> > > > 
> > > > nit: there is a 1 byte hole here (on x86_64)
> > > 
> > > I think even in the current form is ok. The total size of the struct is
> > > not going to change, due to alignment, and the fields will sit in the
> > > same cacheline in both cases.
> > > 
> > > I guess the layout could be changed later if needed.
> > 
> > Ok, I did think it was worth mentioning.
> > But I agree that it doesn't need to be changed at this time.
> 
> Thanks Simon for taking time to review the patch. I'll try to handle it at a
> later point in time.

Thanks, much appreciated.