ethnl_req_get_phydev(9)

💅 ethnl_req_get_phydev(9)

okay so bestie, welcome to the Kernel API Manual ✨ this one's from the ethnl_req_get_phydev(9) page and it's literally all about grabbing the phy_device that this request is targeting — if there even is one 🎀

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🌸 NAME 🌸

ethnl_req_get_phydev — Gets the phy_device targeted by this request, if any. 🦋

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✨ SYNOPSIS ✨

struct phy_device * ethnl_req_get_phydev (const struct ethnl_req_info
*req_info , struct nlattr **tb , unsigned int header , struct
netlink_ext_ack *extack );

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🎀 ARGUMENTS 🎀

• req_info — the ethnl request you're pulling the phy from 🫶
• tb — the netlink attributes array, and it's here purely for error reporting 📋
• header — the netlink header index, also used for error reporting 🔍
• extack — the netlink extended ACK, again for error reporting 💬

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💖 DESCRIPTION 💖

so here's the vibe: if a phy_device is returned, the caller must hold rtnl_lock when calling this function — and must keep holding it until it's fully done interacting with the returned phy_device. 🔒 IOW, caller must hold rtnl_lock unless they know the netdev has no phy_device. no cap, this is the rule 💅

⚠️ fr fr, do not skip the lock thing. it's giving "hold rtnl_lock" for a reason 😭

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🌈 RETURN 🌈

you get a phy_device pointer that corresponds either to the passed phy_index, if one is provided. if not? you get the phy_device attached to the net_device targeted by this request. 🎯

• if there's no targeted net_device, or no phy_device is attached → NULL comes back 🙈
• if the provided phy_index is invalid → an error pointer comes back 💀

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🦋 SEE ALSO 🦋

Kernel file ./net/ethtool/netlink.h, plus all these iconic siblings ✨:

• ethnl_strz_size(9)
• ethnl_put_strz(9)
• ethnl_update_u32(9)
• ethnl_update_u8(9)
• ethnl_update_u8_u32(9)
• ethnl_update_bool32(9)
• ethnl_update_bool(9)
• ethnl_update_binary(9)
• ethnl_update_bitfield32(9)
• ethnl_reply_header_size(9)
• struct ethnl_req_info(9)
• struct ethnl_reply_data(9)
• struct ethnl_request_ops(9)

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and that's the whole page, bestie 💜 this one lives in ./net/ethtool, dated October 2026, and it's lowkey the ethnl_req_get_phydev(9) moment of all time 👑 signed off with a 🍓 and a 🧚 — go hold that lock ✨