Re: [PATCH net-next v2 13/14] net: phy: add Broadcom BCM84881 PHY driver

[Russell King - ARM Linux admin <linux@armlinux.org.uk>]

On Tue, Dec 10, 2019 at 09:34:16AM -0800, Florian Fainelli wrote:
> On 12/9/19 7:19 AM, Russell King wrote:
> > Add a rudimentary Clause 45 driver for the BCM84881 PHY, found on
> > Methode DM7052 SFPs.
> > 
> > Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> 
> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
> 
> > ---
> >  drivers/net/phy/Kconfig    |   6 +
> >  drivers/net/phy/Makefile   |   1 +
> >  drivers/net/phy/bcm84881.c | 269 +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 276 insertions(+)
> >  create mode 100644 drivers/net/phy/bcm84881.c
> > 
> > diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> > index fe602648b99f..41272106dea9 100644
> > --- a/drivers/net/phy/Kconfig
> > +++ b/drivers/net/phy/Kconfig
> > @@ -329,6 +329,12 @@ config BROADCOM_PHY
> >  	  Currently supports the BCM5411, BCM5421, BCM5461, BCM54616S, BCM5464,
> >  	  BCM5481, BCM54810 and BCM5482 PHYs.
> >  
> > +config BCM84881_PHY
> > +	bool "Broadcom BCM84881 PHY"
> > +	depends on PHYLIB=y
> > +	---help---
> > +	  Support the Broadcom BCM84881 PHY.
> 
> Cannot we make this tristate, I believe we cannot until there are more
> fundamental issues (that you just reported) to be fixed, correct?

Indeed.  The problem I saw was that although the bcm84881 has the
PHY correctly described, for whatever reason, the module was not
loaded.

What I think is going in is that with modern udev userspace,
request_module() is not functional, and we do not publish the
module IDs for Clause 45 PHYs via uevent.  Consequently, there
exists no mechanism to load a Clause 45 PHY driver from the
filesystem.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up