ENUM PHY_UPSTREAM(9)

🌸 enum phy_upstream(9) — the Kernel API Manual, bestie edition 💅

okay so welcome to the enum phy_upstream(9) page ✨ this is from the Kernel API Manual, and it's honestly such a little cutie of a page. small. focused. iconic. let's get into it 🫶

---

💖 NAME 💖

enum phy_upstream — this one literally tells you which upstream component a given PHY device is plugged into 🦋 like, what's on the other end of the MII bus? that's the whole vibe check.

so most PHYs? they're attached to an Ethernet MAC controller, no surprises there. but sometimes 👀 there's an intermediate PHY doing media-converter duty, and that one drives another MII interface as its output. it's giving middle-manager energy fr fr 💀

---

✨ SYNOPSIS ✨

enum phy_upstream {
    PHY_UPSTREAM_MAC ,
    PHY_UPSTREAM_PHY

};

look at those two constants. beautiful. no notes. 🎀

---

🌈 Constants 🌈

💜 PHY_UPSTREAM_MAC

the upstream component is a MAC — as in a switch port, or an ethernet controller 🌸 classic. the standard setup. main character energy.

🧚 PHY_UPSTREAM_PHY

the upstream component is a PHY — likely a media converter 💫 so it's a PHY talking to a PHY, which lowkey sounds like a group chat with two of the same person but okay, it makes sense here i promise.

---

🔥 SEE ALSO 🔥

okay bestie this list is long — like, longer than my skincare routine — but every single one of these is part of the family so we're listing all of them, no skipping, periodt 👑

• struct ethtool_cmd(9)
• struct ethtool_drvinfo(9)
• struct ethtool_wolinfo(9)
• struct ethtool_regs(9)
• struct ethtool_eeprom(9)
• struct ethtool_eee(9)
• struct ethtool_modinfo(9)
• struct ethtool_coalesce(9)
• struct ethtool_ringparam(9)
• struct ethtool_channels(9)
• struct ethtool_pauseparam(9)
• enum ethtool_stringset(9)
• enum ethtool_mac_stats_src(9)
• enum ethtool_module_power_mode_policy(9)
• enum ethtool_module_power_mode(9)
• enum ethtool_c33_pse_ext_state(9)
• enum ethtool_c33_pse_ext_substate_mr_mps_valid(9)
• enum ethtool_c33_pse_ext_substate_error_condition(9)
• enum ethtool_c33_pse_ext_substate_mr_pse_enable(9)
• enum ethtool_c33_pse_ext_substate_option_detect_ted(9)
• enum ethtool_c33_pse_ext_substate_option_vport_lim(9)
• enum ethtool_c33_pse_ext_substate_ovld_detected(9)
• enum ethtool_c33_pse_ext_substate_power_not_available(9)
• enum ethtool_c33_pse_ext_substate_short_detected(9)
• enum ethtool_pse_types(9)
• enum ethtool_c33_pse_admin_state(9)
• enum ethtool_c33_pse_pw_d_status(9)
• enum ethtool_podl_pse_admin_state(9)
• enum ethtool_podl_pse_pw_d_status(9)
• enum ethtool_mm_verify_status(9)
• enum ethtool_module_fw_flash_status(9)
• struct ethtool_gstrings(9)
• struct ethtool_sset_info(9)
• enum ethtool_test_flags(9)
• struct ethtool_test(9)
• struct ethtool_stats(9)
• struct ethtool_perm_addr(9)
• struct ethtool_tcpip4_spec(9)
• struct ethtool_ah_espip4_spec(9)
• struct ethtool_usrip4_spec(9)
• struct ethtool_tcpip6_spec(9)
• struct ethtool_ah_espip6_spec(9)
• struct ethtool_usrip6_spec(9)
• struct ethtool_flow_ext(9)
• struct ethtool_rx_flow_spec(9)
• struct ethtool_rxnfc(9)
• struct ethtool_rxfh_indir(9)
• struct ethtool_rxfh(9)
• struct ethtool_rx_ntuple_flow_spec(9)
• struct ethtool_rx_ntuple(9)
• struct ethtool_dump(9)
• struct ethtool_get_features_block(9)
• struct ethtool_gfeatures(9)
• struct ethtool_set_features_block(9)
• struct ethtool_sfeatures(9)
• struct ethtool_ts_info(9)
• struct ethtool_per_queue_op(9)
• struct ethtool_fecparam(9)
• enum ethtool_fec_config_bits(9)
• struct ethtool_link_settings(9)

see? told you. sixty of them. ate and left no crumbs 🍓

---

ngl there's no danger zone on this page, no deprecated stuff, no "undefined behaviour" jumpscare — it's just a tidy little enum and its two constants. a wholesome read. love that for us 🎀

and that's the whole page!! you understood it, i'm so proud 😭💖 this one lives in the kernel file ./include/uapi/linux, dated October 2026, and it goes by enum phy_upstream(9) — mwah, see you in the next manpage bestie 🧚✨