Messages in this thread Patch in this message | | | From | Vladimir Oltean <> | Subject | [RFC PATCH v2 net-next 02/15] phy: introduce the PHY_MODE_ETHTOOL mode for phy_set_mode_ext() | Date | Sat, 23 Sep 2023 16:48:51 +0300 |
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In networking, we have 2 distinct data types:
- phy_interface_t describes the link between a MAC (or MAC-side PCS) and an attached PHY or SFP cage
- enum ethtool_link_mode_bit_indices describes the link between a local PHY and a remote PHY (for example, gigabit RJ45 twisted copper pairs)
Currently, phy_set_mode_ext(PHY_MODE_ETHERNET) takes arguments of the phy_interface_t type, and there is no way to pass an argument of the enum ethtool_link_mode_bit_indices type. The new PHY_MODE_ETHTOOL intends to address that.
It is true that there is currently some overlap between these data types, namely:
phy_interface_t enum ethtool_link_mode_bit_indices ----------------------------------------------------------------- PHY_INTERFACE_MODE_10GKR ETHTOOL_LINK_MODE_10000baseKR_Full_BIT PHY_INTERFACE_MODE_1000BASEKX ETHTOOL_LINK_MODE_1000baseKX_Full_BIT
but those overlaps were deemed to be mistakes, and PHY-to-PHY link modes should only be added to ethtool_link_mode_bit_indices going forward. Thus, I believe that the distinction is necessary, rather than hacking more improper PHY modes. Some of the PHY-to-PHY link modes which may be added in the future (to ethtool_link_mode_bit_indices and not to phy_interface_t) are:
ETHTOOL_LINK_MODE_100000baseKP4_Full_BIT ETHTOOL_LINK_MODE_100000baseCR10_Full_BIT ETHTOOL_LINK_MODE_25000baseKR_S_Full_BIT ETHTOOL_LINK_MODE_25000baseCR_S_Full_BIT
One user of PHY_MODE_ETHTOOL will be the MTIP backplane AN/LT + Lynx SerDes PHY combo, where the backplane autoneg protocol (IEEE 802.3 clause 73) selects the operating PHY-to-PHY link mode.
There are electrical differences between the PHY-to-PHY backplane link modes (like ETHTOOL_LINK_MODE_10000baseKR_Full_BIT) and their non-backplane counterparts (like PHY_INTERFACE_MODE_10GBASER), namely the number of TX signal equalization taps and their configurability. This further justifies distinguishing between them in the generic PHY API.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- v1->v2: rename PHY_MODE_ETHERNET_PHY to PHY_MODE_ETHTOOL at Russell's suggestion
include/linux/phy/phy.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h index 6be348f1fa0e..72ef4afcda81 100644 --- a/include/linux/phy/phy.h +++ b/include/linux/phy/phy.h @@ -39,6 +39,7 @@ enum phy_mode { PHY_MODE_UFS_HS_B, PHY_MODE_PCIE, PHY_MODE_ETHERNET, + PHY_MODE_ETHTOOL, PHY_MODE_MIPI_DPHY, PHY_MODE_SATA, PHY_MODE_LVDS, @@ -52,7 +53,7 @@ enum phy_media { }; enum phy_status_type { - /* Valid for PHY_MODE_ETHERNET */ + /* Valid for PHY_MODE_ETHERNET and PHY_MODE_ETHTOOL */ PHY_STATUS_CDR_LOCK, }; -- 2.34.1
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