[U-Boot] [PATCH] Bugfix: mpc512x_fec MII accesses fail after ethernet transfers

Wolfgang Denk
2009-07-23T19:29:56Z

Dear Thomas D?rfler,

In message <4A637B05.4030306@embedded-brains.de> you wrote:
>
> But I doubt that (re-)calling mpc512x_fec_init_phy before a MII command
> is run is really a good idea. Using the same code for initial init and
> repeated init makes sense, but this function in its current
> implementation also resets the PHY, which forces a new line negotiation
> to occur. IMHO this is NOT needed when we e.g. query the PHY status and
> it would even be contraproductive, if we would change some PHY register
> settings, because these changes would also be reset.

Agreed.

> What COULD make sense is to extract the MII speed register setting
> operation from mpc512x_fec_init_phy() and move it to the
> mpc512x_fec_mii_read/write functions. because this is where it is really
> needed.
>
> Does this make sense to you?

Yes, it does. But we should double-check if setting the MII_SPEED
register is all that should be (re-) initialized.

Best regards,

Wolfgang Denk

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