Re: [net PATCH 1/2] net: phy: Cleanup handling of recent changes to phy_lookup_setting

["Russell King (Oracle)" <linux@armlinux.org.uk>]

On Fri, Apr 04, 2025 at 03:46:01AM +0200, Andrew Lunn wrote:
> On Fri, Apr 04, 2025 at 12:26:15AM +0100, Russell King (Oracle) wrote:
> > On Thu, Apr 03, 2025 at 02:53:22PM -0700, Alexander Duyck wrote:
> > > How is it not a fixed link? If anything it was going to be more fixed
> > > than what you described above.
> > 
> > I had to laugh at this. Really. I don't think you quite understand the
> > case that Andrew was referring to.
> > 
> > While he said MAC to MAC, he's not just referring to two MACs that
> > software can program to operate at any speed, thus achieving a link
> > without autoneg. He is also talking about cases where one end is
> > fixed e.g. by pinstrapping to a specific configuration including
> > speed, and using anything different on the host MAC side results in
> > no link.
> 
> Yep, this is pretty typical of SOHO switches, you use strapping to set
> the port, and it never changes, at least not without a soldering iron
> to take off/add resistors. There are also some SOHO switches which
> have a dedicated 'cpu port' and there is no configuration options at
> all. The CPU MAC must conform to what the switch MAC is doing.

From the sounds of it, Alexander seems to want to use fixed-link
differently - take parameters from firmware, build swnodes, and
set the MAC up for a fixed link with variable "media" type. So
it's not really fixed, but "do what the firmware says". I can't see
that being much different to other platforms which have firmware
that gives us the link parameters.

Presumably in Alexander's case, the firmware also gives link up/down
notifications as well, so it seems to me that this isn't really a
fixed link at all.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!