Re: [net-next PATCH v8 3/4] net: dsa: Add Airoha AN8855 5-Port Gigabit DSA Switch driver

[Christian Marangi <ansuelsmth@gmail.com>]

On Wed, Dec 04, 2024 at 09:24:45AM +0000, Russell King (Oracle) wrote:
> On Wed, Dec 04, 2024 at 10:14:31AM +0100, Christian Marangi wrote:
> > On Wed, Dec 04, 2024 at 10:09:22AM +0100, Maxime Chevallier wrote:
> > > > +	case 5:
> > > > +		phy_interface_set_rgmii(config->supported_interfaces);
> > > > +		__set_bit(PHY_INTERFACE_MODE_SGMII,
> > > > +			  config->supported_interfaces);
> > > > +		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
> > > > +			  config->supported_interfaces);
> > > > +		break;
> > > > +	}
> > > > +
> > > > +	config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
> > > > +				   MAC_10 | MAC_100 | MAC_1000FD;
> > > 
> > > For port 5, you may also add the MAC_2500FD capability as it supports
> > > 2500BASEX ?
> > > 
> > 
> > I didn't account for the CPU port that runs at 2.5. The LAN port are
> > only 1g. Will add or maybe add the 2500FD only for cpu port?
> > 
> > Maybe Russel can help in this?
> 
> *ll* please.

emabrassing... sorry.

> 
> Well, 2500BASE-X runs at 2.5G, so if MAC_2500FD isn't set in the mask,
> validation will fail for 2500BASE-X.
> 
> > > > +		case SPEED_5000:
> > > > +			reg |= AN8855_PMCR_FORCE_SPEED_5000;
> > > > +			break;
> > > 
> > > There's no mention of any mode that can give support for the 5000Mbps
> > > speed, is it a leftover from previous work on the driver ?
> > > 
> > 
> > Added 5000 as this is present in documentation bits but CPU can only go
> > up to 2.5. Should I drop it? Idea was to futureproof it since it really
> > seems they added these bits with the intention of having a newer switch
> > with more advanced ports.
> 
> Is there any mention of supporting interfaces faster than 2500BASE-X ?
>

In MAC Layer function description, they say:
- Support 10/100/1000/2500/5000 Mbps bit rates

So in theory it can support up to that speed.

-- 
	Ansuel