[net-next,v2,0/6] net: dsa: sja1105: phylink updates

Hi,

This series updates the phylink implementation in sja1105 to use the
supported_interfaces bitmap, convert to the mac_select_pcs() interface,
mark as non-legacy, and get rid of the validation method.

As a final step, enable switching between SGMII and 2500BASE-X as it
is a feature that Vladimir desires.

Specifically, the patches in this series:

1. Populates the supported_interfaces bitmap.
2. As a result of the supported_interfaces bitmap being populated,
   sja1105 no longer needs to check the interface mode as phylink
   will do this.
3. Switch away from using phylink_set_pcs(), using the mac_select_pcs()
   method instead.
4. Mark the driver as not-legacy
5. Fill in mac_capabilities using _exactly_ the same conditions as is
   currently used to decide which link modes to support, and convert
   to use phylink_generic_validate()
6. Add brand new support to permit switching between SGMII and
   2500BASE-X modes of operation as per Vladimir's single patch that
   performs steps 1, 2, 5 and 6 in one go.

There are some additional changes in Vladimir's single patch that I
have not included:

* validation of priv->phy_mode[] in sja1105_phylink_get_caps(). The
  driver has already validated the phy_mode for each port in
  sja1105_init_mii_settings(), and a failure here will prevent the
  driver reaching sja1105_phylink_get_caps().

* Changing the decisions on which mac_capabilities to set. Vladimir's
  patch always sets MAC_10FD | MAC_100FD | MAC_1000FD despite the
  current code clearly making the 1G speed conditional on the
  xmii_mode for the port. The change in decision making may be
  visible when in PHY_INTERFACE_MODE_INTERNAL mode, for which
  the phylink_generic_validate() will pass through all the MAC
  capabilities as ethtool link modes.

  Hence, if we have PHY_INTERFACE_MODE_INTERNAL but supports_rgmii[]
  or supports_sgmii[] is non-zero, currently we do not get 1G speeds.
  With Vladimir's additional change, we will get 1G speeds.

  While it is not clear whether that can happen, I feel changing the
  decision making should be a separate patch.

* The decision for MAC_2500FD is made differently -
  sja1105_init_mii_settings() allows PHY_INTERFACE_MODE_2500BASEX
  when supports_2500basex[] is non-zero, and is not based on any other
  condition such as supports_sgmii[] or supports_rgmii[]. Vladimir's
  patch makes it additionally conditional on those supports_.gmii[]
  settings, which is a functional change that should be made in a
  separate patch - and if desired, then sja1105_init_mii_settings()
  should also be updated at the same time.

Consequently, I believe that my previous objections to Vladimir's
single patch approach are well founded and justified, even through
Vladimir is the maintainer of this driver. I have no objection to
the additional changes, I just don't think they should all be wrapped
up into a single patch that converts the way validation is done _and_
also makes a bunch of other functional changes.

RFC->non-RFC: added Vladimir's Reviewed-by's, fixed the typo in the
commit message of patch 6, and removed the phrase at the end of a
comment as requested.

v2: fix the fscking vi fsckups when pasting in attributations.

 drivers/net/dsa/sja1105/sja1105_main.c | 100 ++++++++++++++-------------------
 1 file changed, 42 insertions(+), 58 deletions(-)

Hello:

This series was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Fri, 25 Feb 2022 11:59:23 +0000 you wrote:
> Hi,
> 
> This series updates the phylink implementation in sja1105 to use the
> supported_interfaces bitmap, convert to the mac_select_pcs() interface,
> mark as non-legacy, and get rid of the validation method.
> 
> As a final step, enable switching between SGMII and 2500BASE-X as it
> is a feature that Vladimir desires.
> 
> [...]

Here is the summary with links:
  - [net-next,1/6] net: dsa: sja1105: populate supported_interfaces
    https://git.kernel.org/netdev/net-next/c/a420b757acc4
  - [net-next,2/6] net: dsa: sja1105: remove interface checks
    https://git.kernel.org/netdev/net-next/c/c2b8e1e3d81e
  - [net-next,3/6] net: dsa: sja1105: use .mac_select_pcs() interface
    https://git.kernel.org/netdev/net-next/c/827b4ef2772f
  - [net-next,4/6] net: dsa: sja1105: mark as non-legacy
    https://git.kernel.org/netdev/net-next/c/2d1d548ec144
  - [net-next,5/6] net: dsa: sja1105: convert to phylink_generic_validate()
    https://git.kernel.org/netdev/net-next/c/9c318be13ca0
  - [net-next,6/6] net: dsa: sja1105: support switching between SGMII and 2500BASE-X
    https://git.kernel.org/netdev/net-next/c/83dc4c2af682

You are awesome, thank you!