[U-Boot-Users] IXP4xx Silicon version

[Jonathan Pratt]

> -----Original Message-----
> From: Stefan Roese [mailto:sr at denx.de] 
> Sent: Thursday, 7 June 2007 3:18 PM
> To: u-boot-users at lists.sourceforge.net
> Cc: Jonathan Pratt
> Subject: Re: [U-Boot-Users] IXP4xx Silicon version
> 
> Hi Jonathan,
> 
> On Thursday 07 June 2007, Jonathan Pratt wrote:
> > I'm not sure if anyone else has found it to be a problem but some 
> > boards we recently had built have an IXP425 on them which reports a 
> > Product Revision value 0x2 (lowest four bits of CP15, reg 0).
> 
> Seems that Intel has released a new revision of the CPU.

I couldn't find any reference to it in the Intel documentation (but the
web site is not friendly to navigate so I didn't try all that hard).

> > This is only a
> > problem because the file
> >
> > cpu/ixp/npe/npe.c
> >
> > uses this field in the npe_initialize function to decide how to 
> > determine how many ethernet ports there are. Unfortunately the case 
> > statement only accounts for revision values 0x0
> > (IX_FEATURE_CTRL_SILICON_TYPE_A0) and 0x01
> > (IX_FEATURE_CTRL_SILICON_TYPE_B0) so that the existing code doesn't 
> > think that these processors have any ethernet ports 
> available. I found 
> > that by adding a 'default:' statement before line #639 remedied the 
> > problem. This file is part of u-boot, not the Intel npe library.
> 
> Would be interesting to know, what the differences of this 
> new IXP425 revision are before "blindly" selecting default 
> for Rev. A or Rev. B.

The 'B' option uses the reported capabilities of the device (through the
ixFeatureCtrlComponentCheck function in the npe library) which reads the
feature control register to get the infomration. I would have thought
that (for determining whether ethernet MAC's are present) this would be
a pretty safe bet.

> > Since it seems that someone is immanently about to release 
> a patch on 
> > the npe stuff anyway, would it be too much trouble to add 
> the 'default:'
> > statement or otherwise handle this product revision?
> 
> Yes, "someone" is waiting for another revised patch. I could 
> of course add this statement, but I can't test since I don't 
> have IXP hardware right now. 
> Did you test this change successfully on both ethernet ports?

Sorry - this hardware only utilises one of the MACs (npe B = MAC 0).
 
> Best regards,
> Stefan
> 
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Thanks
Jonathan Pratt