[U-Boot] [PATCH] arm: mxs: fix mac address of second interface

[Michael Heimpold <mhei@heimpold.de>]

Hi Marek,

Am Sonntag, 16. August 2015, 00:49:36 schrieb Marek Vasut:
> On Sunday, August 16, 2015 at 12:16:21 AM, Michael Heimpold wrote:
> > In the rare case that an overflow occurs, propagate it.
> 
> Hi!
> 
> > Signed-off-by: Michael Heimpold <mhei@heimpold.de>
> > Cc: Stefano Babic <sbabic@denx.de>
> > Cc: Marek Vasut <marex@denx.de>
> > CC: Fabio Estevam <fabio.estevam@freescale.com>
> > ---
> >  arch/arm/cpu/arm926ejs/mxs/mxs.c |   12 ++++++++++--
> >  1 file changed, 10 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/arm/cpu/arm926ejs/mxs/mxs.c
> > b/arch/arm/cpu/arm926ejs/mxs/mxs.c index b1d8721..42057ad 100644
> > --- a/arch/arm/cpu/arm926ejs/mxs/mxs.c
> > +++ b/arch/arm/cpu/arm926ejs/mxs/mxs.c
> > @@ -238,11 +238,19 @@ int cpu_eth_init(bd_t *bis)
> > 
> >  __weak void mx28_adjust_mac(int dev_id, unsigned char *mac)
> >  {
> > +	uint32_t data;
> > +
> >  	mac[0] = 0x00;
> >  	mac[1] = 0x04; /* Use FSL vendor MAC address by default */
> > 
> > -	if (dev_id == 1) /* Let MAC1 be MAC0 + 1 by default */
> > -		mac[5] += 1;
> > +	if (dev_id == 1) { /* Let MAC1 be MAC0 + 1 by default */
> > +		data = (mac[3] << 16) | (mac[4] << 8) | mac[5];
> > +		data++;
> > +
> > +		mac[3] = (data >> 16) & 0xff;
> > +		mac[4] = (data >> 8) & 0xff;
> > +		mac[5] = data & 0xff;
> > +	}
> 
> I'm not very fond of the added complexity. If an overflow happens,

At least for me, that would be the "algorithm of least surprise" and
I don't feel that this is so complex but YMMV :-)

> the last nibble just becomes 0x00, which should be okayish. In case
> you need some sort of special handling of the ethernet address, I'd
> suggest to implement your own thing in board file.

If this is a NAK, then yes, I can handle this in every board file where needed
because I've to adjust the vendor part anyway...

> 
> Best regards,
> Marek Vasut

Best regards,
Michael