Re: [RFC PATCH net-next 2/8] phy: introduce the PHY_MODE_ETHERNET_PHY mode for phy_set_mode_ext()
From: Sean Anderson <hidden>
Date: 2023-08-21 17:31:07
Also in:
linux-devicetree, linux-phy, lkml
On 8/17/23 11:06, Vladimir Oltean wrote:
As opposed to PHY_MODE_ETHERNET which takes a phy_interface_t as is expected to be used by an Ethernet MAC driver, PHY_MODE_ETHERNET takes an enum ethtool_link_mode_bit_indices and expects to be used by an Ethernet PHY driver. It is true that the phy_interface_t type also contains definitions for PHY_INTERFACE_MODE_10GKR and PHY_INTERFACE_MODE_1000BASEKX, but those were deemed to be mistakes, and shouldn't be used going forward, when 10GBase-KR and 1GBase-KX are really link modes. Thus, I believe that the distinction is necessary, rather than hacking more improper PHY modes.
10GBase-KR and 1000Base-KX are both electrically (e.g. link mode) and functionally (e.g. phy mode) different from 10GBase-R and 1000Base-X due to differing autonegotiation. So the phy modes are still relevant, and should still be used to ensure the correct form of autonegotiation is selected. That said, I do agree that from the phy's (serdes's) point of view, there are only electrical differences between these modes. However, I'm not sure we need to have a separate mode here. I think this would only be necessary if there were electrically-incompatible modes which shared the same signalling. E.g. if 802.3 decided that they wanted a "long range backplane ethernet" or somesuch with different drive/equalization requirements from 1000BASE-KX et al. but with the same signalling. Otherwise, we can infer the link mode from the phy mode. --Sean
quoted hunk ↗ jump to hunk
In particular to the Lynx SerDes, it can be used (as the PMA/PMD layer) in conjunction with a separate backplane AN/LT block to form a full-fledged copper backplane Ethernet PHY. The configuration of the lanes is relatively similar to what is done for a typical MAC-to-PHY link, except that we allow tuning the electrical equalization parameters of the link (support for which will come as a separate change). Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- 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 456d21c67e4f..7e10761303fc 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_ETHERNET_PHY, PHY_MODE_MIPI_DPHY, PHY_MODE_SATA, PHY_MODE_LVDS,