[U-Boot] [PATCH v4 1/3] net: Adds Fast Ethernet Controller driver for Armada100

[Ajay Bhargav]

----- "Mike Frysinger" <vapier at gentoo.org> wrote:

> On Tuesday, August 30, 2011 01:44:40 Ajay Bhargav wrote:
> > +static void update_hash_table_mac_address(struct armdfec_device
> *darmdfec,
> > +					  u8 *oaddr, u8 *addr)
> > +{
> > +	u32 mach;
> > +	u32 macl;
> > +
> > +	/* Delete old entry */
> > +	if (oaddr) {
> > +		mach = (oaddr[0] << 8) | oaddr[1];
> > +		macl = (oaddr[2] << 24) | (oaddr[3] << 16) |
> > +			(oaddr[4] << 8) | oaddr[5];
> > +		add_del_hash_entry(darmdfec, mach, macl, 1, 0, HASH_DELETE);
> > +	}
> > +
> > +	/* Add new entry */
> > +	mach = (addr[0] << 8) | addr[1];
> > +	macl = (addr[2] << 24) | (addr[3] << 16) | (addr[4] << 8) |
> addr[5];
> > +	add_del_hash_entry(darmdfec, mach, macl, 1, 0, HASH_ADD);
> > +}
> > ...
> > +static int armdfec_init(struct eth_device *dev, bd_t *bd)
> > +{
> > ...
> > +	update_hash_table_mac_address(darmdfec, dev->enetaddr,
> dev->enetaddr);
> 
> i think something got lost along the way here :)
> 
> you'll probably want to have oaddr[] be a static local in 
> update_hash_table_mac_address and use that to delete the old one when
> it 
> differs from the new one, and then copy the new one into the static
> local.
> -mike

You can have multiple entries in Hash table for different MAC addresses.
The reason old entry is deleted because it may be possible that hash entry
in the list is skipped but not invalidated so the same entry is made valid
in the list after removing the old one and updating list with new entry.
The calculated has for a particular MAC address is going to be same.

Thanks,
Ajay Bhargav