Re: [ECOS] Settign ethernet speed and duplex

[Gary Thomas <gary at mlbassoc dot com>]

Laurie Gellatly wrote:
> Nick,
> You've never seen auto negotiation fail then like I have.
> If auto negotiation works the way its suppose to then I agree, you're better
> off leaving it like that.
> Reality unfortunatly does not always follow the best laid plans of mice and
> men.
>
> Regardless of what you and I might think the customer would still like to
> set speed and duplex manually so....
> Back to the original question, how should this be provided for?
>
> Thanks for your comments.			...Laurie:{)

Since this needs to be done in the ethernet driver, add some options for
it in the CDL there.  If you use the PHY package as well, there are functions
you can call to manage this.  At least that's what the design was for, but
as Nick said, it's seldom [if ever] been necessary to force a PHY into a mode
that it can't auto-negotiate into.

> -----Original Message-----
> From: ecos-discuss-owner@ecos.sourceware.org
> [mailto:ecos-discuss-owner@ecos.sourceware.org]On Behalf Of Nick Garnett
> Sent: Friday, 15 September 2006 7:19 PM
> To: laurie.gellatly@netic.com
> Cc: ecos-discuss@ecos.sourceware.org
> Subject: Re: [ECOS] Settign ethernet speed and duplex
>
>
> "Laurie Gellatly" <laurie.gellatly@netic.com> writes:
>
> > Hi All,
> > I'm writing a new ethernet chip driver.
> > The chip (with built in PHY) support setting of speed (10/100) and duplex.
> > That's pretty easy to do in the driver but I'm lost in how it should be
> > connected to the application code.
> > I thought it might be an ioctl key but can't find anything to help me.
> >
> > So, my question is, what is the 'right way' for this to be implemented and
> > are there examples I can follow?
>
> Generally applications don't get involved with this. The PHYs at each
> end of the the wire negotiate the best speed and duplicity at
> initialization and that's where it stays. Sometimes it is necessary to
> prod the PHY to make it negotiate, but most just do it
> automatically. Sometimes it is also necessary to query the PHY for the
> settings and transfer them to the MAC. For a combined MAC+PHY I would
> expect all of this to happen automatically.
>
> I'm not sure why an application would need to change these
> settings. You cannot change the duplex setting, since that depends on
> the nature of the far end. If the PHYs have negotiated 10MB/s then
> trying to raise it to 100MB/s will not work and I don't see any
> advantage in reducing it from 100 to 10.
>
>
> --
> Nick Garnett                                 eCos Kernel Architect
> http://www.ecoscentric.com            The eCos and RedBoot experts
>
>
> --
> Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
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--
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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