Re: [PATCH 2/5] phy: core: add PHY_MODE_ETHERNET

[Grygorii Strashko]

hi Russell,

On 11/7/18 6:42 PM, Russell King - ARM Linux wrote:
> On Wed, Nov 07, 2018 at 06:36:14PM -0600, Grygorii Strashko wrote:
> > Add new PHY's mode to be used by Ethernet PHY interface drivers or
> > multipurpose PHYs like serdes. It will be reused in further changes.
> >
> > Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> > ---
> >   include/linux/phy/phy.h | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> > index b17e770..02c9ef0 100644
> > --- a/include/linux/phy/phy.h
> > +++ b/include/linux/phy/phy.h
> > @@ -42,6 +42,7 @@ enum phy_mode {
> >   	PHY_MODE_UFS_HS_A,
> >   	PHY_MODE_UFS_HS_B,
> >   	PHY_MODE_PCIE,
> > +	PHY_MODE_ETHERNET,
>
> Are you sure about this - we already have a bunch of "ethernet" modes
> that are more specific, like PHY_MODE_SGMII, PHY_MODE_2500SGMII and
> PHY_MODE_10GKR which require PHYs to be configured differently.  Having
> a very generic "ethernet" mode brings up questions about when it should
> be used vs the more specific modes.

yes. the idea of this series is to split PHY mode on - PHY mode (generic)
and PHY submode (subsystem specific), so multi-functional PHY like serdes will do
(for example):

 phy_set_mode_ext(port->comphy, PHY_MODE_ETHERNET, PHY_INTERFACE_MODE_SGMII);
 where PHY_INTERFACE_MODE_SGMII is defined by phy_interface_t enum.

instead of

 phy_set_mode(port->comphy, PHY_MODE_SGMII);

In patches 3-5 I've converted users of existing PHY "ethernet" modes to use
this approach and, finally, in patch 5 removed
   PHY_MODE_SGMII/2500SGMII/QSGMII/10GKR

> (I've already mentioned that the SGMII modes are mis-named, since
> they also apply to 1000base-X and 2500base-X - the only difference
> is how one 16-bit word in the data stream is used which has no effect
> on the PHY.)

--
regards,
-grygorii