Re: [dpdk-dev] [PATCH] net/ixgbe: 10GBASE-T SFP+ copper support

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Ido Goshen [mailto:Ido@cgstowernetworks.com]
> Sent: Sunday, April 28, 2019 7:54 AM
> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Lu, Wenzhuo <wenzhuo.lu@intel.com>
> Cc: dev@dpdk.org
> Subject: RE: [PATCH] net/ixgbe: 10GBASE-T SFP+ copper support
> 
> 
> 
> > -----Original Message-----
> > From: Ananyev, Konstantin <konstantin.ananyev@intel.com>
> > Sent: Friday, April 26, 2019 3:13 PM
> > To: Ido Goshen <Ido@cgstowernetworks.com>; Lu, Wenzhuo
> > <wenzhuo.lu@intel.com>
> > Cc: dev@dpdk.org
> > Subject: RE: [PATCH] net/ixgbe: 10GBASE-T SFP+ copper support
> >
> >
> >
> > > > > From: Ido Goshen <ido@cgstowernetworks.com>
> > > > >
> > > > > 10BASE-T SFP+ copper transceivers become cheaper and popular So
> > > > > far those were blocked by ixgbe as “unsupported”.
> > > > > e.g.
> > > > > 	eth_ixgbe_dev_init(): Unsupported SFP+ Module
> > > > > 	eth_ixgbe_dev_init(): Hardware Initialization Failure: -19
> > > > > 	EAL: Requested device 0000:0a:00.0 cannot be used
> > > > >
> > > > > This patch expands the usage of allow_unsupported_sfp to be more
> > > > > general and makes ixgbe more tolerant to unknown SFPs
> > > >
> > > >
> > > > I don't think it is a good idea to change the base code to blindly
> > > > allow unknown SFPs.
> > > > Again in eth_ixgbe_dev_init() we do set
> > > > hw->allow_unsupported_sfp = 1;
> > > > so the function below will return success anyway,
> > >
> > > what's the reason to not allow unknown SFPs?
> > > as is they are explicitly blocked and not working anyway, why not give
> > them a chance?
> >
> > From my perspective the question should be opposite: why to allow it?
> > ixgbe base code is developed and maintained by Intel ND team for several
> > platforms.
> > It should be some good reason to change it inside DPDK project only.
> > As I said,  in eth_ixgbe_dev_init() we already set hw->allow_unsupported_sfp
> > = 1, so unknown spf should be allowed by DPDK ixgbe PMD.
> > So what exact problem you are trying to solve here?
> > Konstantin
> 
> The problem is that 10GBASE-T copper transceivers are not working just because they are unknown
> http://www.eoptolink.com/products/copper-10g-sfp
> 
> The hw->allow_unsupported_sfp is used too late in
> https://git.dpdk.org/next/dpdk-next-net-intel/tree/drivers/net/ixgbe/base/ixgbe_phy.c#n1530
> And if we've already got out earlier in
> https://git.dpdk.org/next/dpdk-next-net-intel/tree/drivers/net/ixgbe/base/ixgbe_phy.c#n1507

As I can read the code that check is for 1G SFPs.
So if you getting out here, then comp_codes_10g == 0 here,
and it means that given SFP is not recognized as 10G one.
I wonder why that happens?

As I can see comp_codes_10g should be initialized at line 1314:
status = hw->phy.ops.read_i2c_eeprom(hw,
                                                     IXGBE_SFF_10GBE_COMP_CODES,
                                                     &comp_codes_10g);

> The device cannot be used
> The patch tries to make the hw->allow_unsupported_sfp more general and in case it is set (always in dpdk)
> change any return status of IXGBE_ERR_SFP_NOT_SUPPORTED to IXGBE_SUCCESS with ixgbe_phy_unknown
> 
> Other suggestions how to make 10GBASE-T copper work?
> 
> >
> > >
> > > More inputs
> > > 1. i40e already does support it (I didn't go deep into it but it just
> > > seems less strict on hw_init) 2. even with ixgbe it can work, because
> > unsupported is only checked by ixgbe_init_hw
> > >      so if the SFP is inserted after the app has started it does work
> > >      kind of inconsistent
> > >
> > > >
> > > > >
> > > > > Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
> > > > > ---
> > > > >  drivers/net/ixgbe/base/ixgbe_phy.c  | 22 +++++++++++-----------
> > > > > drivers/net/ixgbe/base/ixgbe_x550.c |  3 +++
> > > > >  2 files changed, 14 insertions(+), 11 deletions(-)
> > > > >
> > > > > diff --git a/drivers/net/ixgbe/base/ixgbe_phy.c
> > > > > b/drivers/net/ixgbe/base/ixgbe_phy.c
> > > > > index dd118f9..ff96afc 100644
> > > > > --- a/drivers/net/ixgbe/base/ixgbe_phy.c
> > > > > +++ b/drivers/net/ixgbe/base/ixgbe_phy.c
> > > > > @@ -1527,18 +1527,9 @@ s32
> > > > > ixgbe_identify_sfp_module_generic(struct
> > > > ixgbe_hw *hw)
> > > > >  			if (hw->phy.type == ixgbe_phy_sfp_intel) {
> > > > >  				status = IXGBE_SUCCESS;
> > > > >  			} else {
> > > > > -				if (hw->allow_unsupported_sfp == true) {
> > > > > -					EWARN(hw,
> > > > > -						"WARNING: Intel (R)
> > > > Network Connections are quality tested using Intel (R) Ethernet
> > > > > Optics. "
> > > > > -						"Using untested modules is
> > > > not supported and may cause unstable operation or damage
> > > > > to the module or the adapter. "
> > > > > -						"Intel Corporation is not
> > > > responsible for any harm caused by using untested modules.\n");
> > > > > -					status = IXGBE_SUCCESS;
> > > > > -				} else {
> > > > > -					DEBUGOUT("SFP+ module not
> > > > supported\n");
> > > > > -					hw->phy.type =
> > > > > +				hw->phy.type =
> > > > >  						ixgbe_phy_sfp_unsupported;
> > > > > -					status =
> > > > IXGBE_ERR_SFP_NOT_SUPPORTED;
> > > > > -				}
> > > > > +				status = IXGBE_ERR_SFP_NOT_SUPPORTED;
> > > > >  			}
> > > > >  		} else {
> > > > >  			status = IXGBE_SUCCESS;
> > > > > @@ -1546,6 +1537,15 @@ s32
> > > > > ixgbe_identify_sfp_module_generic(struct
> > > > ixgbe_hw *hw)
> > > > >  	}
> > > > >
> > > > >  out:
> > > > > +	if (status == IXGBE_ERR_SFP_NOT_SUPPORTED &&
> > > > > +			hw->allow_unsupported_sfp) {
> > > > > +		PMD_INIT_LOG(WARNING,
> > > > > +				"WARNING: Intel (R) Network Connections
> > > > are quality tested using Intel (R) Ethernet Optics. "
> > > > > +				"Using untested modules is not supported
> > > > and may cause unstable
> > > > > +operation or damage to the module or
> > > > > the adapter. "
> > > > > +				"Intel Corporation is not responsible for any
> > > > harm caused by using untested modules.\n");
> > > > > +		hw->phy.type = ixgbe_phy_unknown;
> > > > > +		status = IXGBE_SUCCESS;
> > > > > +	}
> > > > >  	return status;
> > > > >
> > > > >  err_read_i2c_eeprom:
> > > > > diff --git a/drivers/net/ixgbe/base/ixgbe_x550.c
> > > > > b/drivers/net/ixgbe/base/ixgbe_x550.c
> > > > > index a920a14..212d9a0 100644
> > > > > --- a/drivers/net/ixgbe/base/ixgbe_x550.c
> > > > > +++ b/drivers/net/ixgbe/base/ixgbe_x550.c
> > > > > @@ -1539,6 +1539,9 @@ STATIC s32
> > > > ixgbe_supported_sfp_modules_X550em(struct ixgbe_hw *hw, bool
> > > > *linear)
> > > > >  		*linear = false;
> > > > >  		break;
> > > > >  	case ixgbe_sfp_type_unknown:
> > > > > +		if (hw->allow_unsupported_sfp)
> > > > > +			return IXGBE_SUCCESS;
> > > > > +		/* fall through */
> > > > >  	case ixgbe_sfp_type_1g_cu_core0:
> > > > >  	case ixgbe_sfp_type_1g_cu_core1:
> > > > >  	default:
> > > > > --
> > > > > 1.9.1