Subject: Re: [PATCH RFC 00/10] net: pcs: xpcs: cleanups batch 1

From: "Russell King (Oracle)" <[email-masked]>
Date: Thu, 26 Sep 2024 12:41:27 +0100

On Wed, Sep 25, 2024 at 04:43:37PM +0300, Vladimir Oltean wrote:
> Hi Russell,
> 
> On Mon, Sep 23, 2024 at 03:00:26PM +0100, Russell King (Oracle) wrote:
> > First, sorry for the bland series subject - this is the first in a
> > number of cleanup series to the XPCS driver.
> 
> I presume you intend to remove the rest of the exported xpcs functions
> as well, in further "batches". Could you share in advance some details
> about what you plan to do with xpcs_get_an_mode() as used in stmmac?

I've been concentrating more on the sja1105 and wangxun users with this
cleanup, as changing stmmac is going to be quite painful - so I've left
this as something for the future. stmmac already stores a phylink_pcs
pointer, but we can't re-use that for XPCS because stmmac needs to know
that it's an XPCS vs some other PCS due to the direct calls such as
xpcs_get_an_mode() and xpcs_config_eee().

When I was working on EEE support at phylink level, I did try to figure
out what xpcs_config_eee() is all about, what it's trying to do, why,
and how it would fit into any phylink-based EEE scheme, but I never got
very far with that due to lack of documentation.

So, at the moment I have no plans to touch the prototypes of
xpcs_get_an_mode(), xpcs_config_eee() nor xpcs_get_interfaces(). With
the entire patch series being so large already, I'm in no hurry to add
patches for this - which would need yet more work on stmmac that I'm
no longer willing to do.

> 	if (xpcs_get_an_mode(priv->hw->xpcs, mode) != DW_AN_C73))
> 
> I'm interested because I actually have some downstream NXP patches which
> introduce an entirely new MLO_AN_C73 negotiating mode in phylink (though
> they don't convert XPCS to it, sadly). Just wondering where this is going
> in your view.

To give a flavour of what remains:

net: pcs: xpcs: move Wangxun VR_XS_PCS_DIG_CTRL1 configuration
net: pcs: xpcs: correctly place DW_VR_MII_DIG_CTRL1_2G5_EN
net: pcs: xpcs: use dev_*() to print messages
net: pcs: xpcs: convert to use read_poll_timeout()
net: pcs: xpcs: add _modify() accessors
net: pcs: xpcs: use FIELD_PREP() and FIELD_GET()
net: pcs: xpcs: convert to use linkmode_adv_to_c73()
net: pcs: xpcs: add xpcs_linkmode_supported()
net: mdio: add linkmode_adv_to_c73()
net: pcs: xpcs: move searching ID list out of line
net: pcs: xpcs: rename xpcs_get_id()
net: pcs: xpcs: move definition of struct dw_xpcs to private header
net: pcs: xpcs: provide a helper to get the phylink pcs given xpcs
net: pcs: xpcs: pass xpcs instead of xpcs->id to xpcs_find_compat()
net: pcs: xpcs: don't use array for interface
net: pcs: xpcs: remove dw_xpcs_compat enum

which looks like this on the diffstat:

 drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c |   2 +-
 drivers/net/pcs/pcs-xpcs-nxp.c                    |  24 +-
 drivers/net/pcs/pcs-xpcs-wx.c                     |  51 +--
 drivers/net/pcs/pcs-xpcs.c                        | 521 +++++++++-------------
 drivers/net/pcs/pcs-xpcs.h                        |  42 +-
 include/linux/mdio.h                              |  40 ++
 include/linux/pcs/pcs-xpcs.h                      |  19 +-
 7 files changed, 303 insertions(+), 396 deletions(-)

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