[U-Boot] [PATCH] tsec: Wait for auto-negotiation to complete without link

[Peter Tyser]

Sorry for the delayed response,

On Tue, 2009-02-10 at 11:31 -0600, Scott Wood wrote:
> On Tue, Feb 10, 2009 at 08:59:11AM -0500, Jerry Van Baren wrote:
> > That is my reasoning behind my statement that we can generally ignore 
> > the autonegotiation <-> fixed configuration case because the odds of it 
> > working properly are poor anyway.
> 
> I'm not fond of giving up any ability to support a configuration just
> because some people get it wrong (including configurations where the
> human *can't* screw it up because the fixed end is some old hub or NIC
> that doesn't support anything other than 10Mbit, half-duplex), especially
> when the benefit of not supporting it is so low.
> 
> > Having said all that, I don't have any problem with using 3.5 seconds as 
> > the safe timeout value.  it isn't worth timing out too soon just to 
> > shave 0.5 or even 1.0 seconds off the negotiation timeout time.
> 
> OK, good. :-)

I agree, I'd prefer to err on the conservative side too.  The spec Jerry
mentioned was for a 100M PHY.  I'm guessing it could take longer for a
1000M PHY...  I've looked around a fair bit and couldn't find anything
concrete either.  I see a few references to a 4.5 second autonegotiation
timeout in the Linux kernel (e1000 and e1000e drivers), but of course no
mention of where those numbers came from.  I see timeout values of 4 and
5 seconds in U-Boot also.

What if I keep this patch as is, then submit an additional patch which
would replace all PHY_AUTONEGOTIATE_TIMEOUT references with
CONFIG_SYS_PHY_AUTONEG_TIMEOUT.  A conservative default value of 4.5
seconds would be assigned to CONFIG_SYS_AUTONEG_TIMEOUT in net.h, but
this could be overridden by board config files if wanted/needed?

Thanks,
Peter