[U-Boot-Users] MPC5121 (and MPC5200) ethernet initialization delay

Stefan Roese
2007-12-18T05:20:44Z

On Tuesday 18 December 2007, Chris Morgan wrote:
> One of the hardware guys speculated about the autonegotation being the
> cause of the delay so I guess it has at least a few votes now. I'm
> hoping for a Freescale person on this list to verify the cause of the
> issue as something we can't just change a few registers and fix.
>
> If Wolfgang is ok with not initializing the hardware before use then
> doesn't that fit with holding off the ethernet initialization until
> there is a function call in the code that requires accessing ethernet?
> We aren't using any boot commands that use networking so while we have
> ethernet enabled in our board configuration for debug and flashing it
> isn't necessary in most boot situations. If initialization on demand
> of the ethernet device was acceptable we could probably have someone
> work on a patch to do so. Just want to get approval that the idea is
> sane and acceptable for inclusion in u-boot, if properly implemented.

Let me check if I understand this correctly. Your U-Boot has a delay of
approx. 2 seconds upon booting (most likely waiting for autonegotiation to
complete), even when you don't use ethernet in U-Boot at all?

This is not what should happen. The targets I know best (PPC4xx) initiate the
autonegotiation only when the ethernet interface is used. Upon TFTP download
or something like this. So there should be no delay at all in U-Boot related
to this ethernet initialization when you don't use ethernet.

Best regards,
Stefan

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