sfp_select_interface(9)

💅 sfp_select_interface(9) — a Kernel API Manual moment

okay so bestie, welcome to sfp_select_interface from the Kernel API Manual — yes it's a section 9 page, yes it's kernel-internal, and yes we're gonna get through it together 🫶

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✨ NAME ✨

sfp_select_interface — the girl whose whole job is picking the right phy_interface_t mode. that's it, that's the gig 💅

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🌸 SYNOPSIS 🌸

phy_interface_t sfp_select_interface (struct sfp_bus *bus , const
       unsigned long *link_modes );

like, literally two args and a return value, we love a low-maintenance icon ✨

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🎀 ARGUMENTS 🎀

• bus — a pointer to the struct sfp_bus structure for the sfp module. yes bestie, the whole bus. it's giving main character energy 👑
• link_modes — ethtool link modes mask. that's the vibe check input, ok? memorize it 🦋

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🔥 DESCRIPTION 🔥

so what does she actually do? she derives the phy_interface_t mode for the SFP module from the link modes mask. like she looks at the mask and goes "okay, this one" — no cap, that's the entire plot 😭

not me being obsessed with how clean that is. one input, one derived mode, periodt 💜

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🌈 SEE ALSO 🌈

the whole friend group, fr fr — go say hi:

• Kernel file ./drivers/net/phy/sfp-bus.c
• struct sfp_bus(9)
• sfp_bus_put(9)
• sfp_get_module_info(9)
• sfp_get_module_eeprom(9)
• sfp_get_module_eeprom_by_page(9)
• sfp_upstream_start(9)
• sfp_upstream_stop(9)
• sfp_upstream_set_signal_rate(9)
• sfp_bus_find_fwnode(9)
• sfp_bus_add_upstream(9)
• sfp_bus_del_upstream(9)
• sfp_get_name(9)

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ok that's the whole page bestie, you ate that 🍓

and a lil sign-off: this one lives in ./drivers/net/phy, dated October 2026 💖 slay, go read sfp_bus(9) next, mwah 🧚