[U-Boot] [PATCH] eth: dtsec: fix TBI ANA setting bug in dtsec_configure_serdes()

[Shaohui Xie]

> -----Original Message-----
> From: York Sun [mailto:yorksun at freescale.com]
> Sent: Thursday, November 26, 2015 1:03 AM
> To: Xie Shaohui-B21989; Ciubotariu Codrin Constantin-B43658
> Cc: Yuanzheng Li; u-boot at lists.denx.de; Liu Dave-R63238
> Subject: Re: [PATCH] eth: dtsec: fix TBI ANA setting bug in
> dtsec_configure_serdes()
> 
> + Experts
> 
> On 11/24/2015 11:04 PM, Yuanzheng Li wrote:
> > The TBI_ANA register is configurated with the wrong value 0x4001,
> > refer to QorIQ Data Path Acceleration Architecture (DPAA) Reference
> Manual.
> > It set the reserved areas, bit 1 and bit 11 to bit 15 in big endian,
> > which should be cleared. But the normal functions of the
> > auto-negotiation, e.g. Pause and Full Duplex, do not be set.
[S.H] The value 0x4001 is so special, as mentioned, it does not match the 
DPAA RM, So I dig some docs and found AN3869, in which the 0x4001 is the
desired one to write to TBI_ANA for SGMII.
 
> >
> > There is no problem in the p2041rdb board, because the ppc is
> > connected directly with the phy chip which support auto-negotiation by
> > default in SGMII interface. But the link problem will occur when it is
> > connected with a switch chip like BCM5389, the switch chip disable
> > auto-negotiation by default, and the ppc also disable
> > auto-negotiation, then there is no link between them.
[S.H] This seems a phyless connection. If BCM5389 disables AN, then PPC should
Also disable AN by setting TBI_CR.

> >
> > So use the vlue TBIANA_SETTINGS to enable the ppc's auto-negotiation.
[S.H] The TBI_ANA is " AN Advertisement Register ", it does not enable/disable AN.
A proper way should be to distinguish the phy and phyless connections and configure
The TBI registers accordingly.

Thanks,
Shaohui

> >
> > Signed-off-by: Yuanzheng Li <liyuanzheng01 at 163.com>
> > Cc: York Sun <yorksun at freescale.com>
> > ---
> >  drivers/net/fm/eth.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/net/fm/eth.c b/drivers/net/fm/eth.c index
> > eb8e936..78c0988 100644
> > --- a/drivers/net/fm/eth.c
> > +++ b/drivers/net/fm/eth.c
> > @@ -81,7 +81,7 @@ qsgmii_loop:
> >  	tsec_local_mdio_write(phyregs, in_be32(&regs->tbipa), 0, TBI_TBICON,
> >  			TBICON_CLK_SELECT);
> >  	tsec_local_mdio_write(phyregs, in_be32(&regs->tbipa), 0, TBI_ANA,
> > -			TBIANA_SGMII_ACK);
> > +			TBIANA_SETTINGS);
> >  	tsec_local_mdio_write(phyregs, in_be32(&regs->tbipa), 0,
> >  			TBI_CR, TBICR_SETTINGS);
> >  #endif
> >
> 
> Yuanzheng,
> 
> After your change, TBIANA_SGMII_ACK is not used and should be removed.
> 
> Shaohui and Codrin,
> 
> Please comment.
> 
> York