[U-Boot] [PATCH v2 5/9] AVR32: macb - Disable 100mbps if clock is slow

Jean-Christophe PLAGNIOL-VILLARD
2009-01-28T17:23:22Z

> >> +
> >> +#ifdef CONFIG_MACB_FORCE10M
> >> + printf("%s: 100Mbps is not supported on this board - forcing 10Mbps.\n",
> >> + netdev->name);
> >> +
> >> + adv &= ~ADVERTISE_100FULL;
> >> + adv &= ~ADVERTISE_100HALF;
> >> + adv &= ~ADVERTISE_100BASE4;
> >> +#endif
> > not a fan
> > could you be more specific about the problem?
> >
> > Best Regards,
> > J.
> >
>
> On the EVK1100 board, the CPU (UC3A0512) is connected to the PHY via an
> RMII bus. This requires the CPU clock to be at least 50 MHz.
> Unfortunately, the chip on current EVK1100 boards may be unable to run
> at more than 50 MHz, and with the oscillator on the board, the closest
> frequency we can generate is 48 MHz.
IMHO It's a HW design error to not use the MII
>
> This patch makes it possible to limit the macb to 10 MBit for this
> case. We are open for suggestions for other solutions.
I guest you may need to disable the phy auto config mode and force him to be
see as a 10Mbps phy evenif it's a 10/100

Best Regards,
J.