tb_path_discover(9)

💅 tb_path_discover(9) — the kernel API manual, but make it make sense

okay so bestie, welcome to tb_path_discover(9) from the Kernel API Manual ✨ this is the Thunderbolt path-discovery glow-up you didn't know you needed, and tbh it's lowkey iconic.

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🌈 SYNOPSIS

struct tb_path * tb_path_discover (struct tb_port *src , int src_hopid ,
       struct tb_port *dst , int dst_hopid , struct tb_port **last , const char
       *name , bool alloc_hopid );

like, that's the whole vibe. seven args. she's thorough. 💅

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🎀 ARGUMENTS

• src — first input port of a path. the starting point, the main character, where the whole journey begins 🫶
• src_hopid — starting HopID of a path (-1 if don't care). pass -1 and you're basically saying "idk, surprise me" 🙈
• dst — expected destination port of the path (NULL if don't care). again with the not-caring, and honestly? valid.
• dst_hopid — HopID to the dst (-1 if don't care). same energy, you see the pattern 👑
• last — last port is filled here if not NULL. so if you hand her a spot, she'll write the last port into it, no cap 💖
• name — name of the path. give her a cute label fr fr
• alloc_hopid — allocate HopIDs for the ports. flip this on and she starts handing out HopIDs to everyone she visits like party favours ✨

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🦋 DESCRIPTION

So the way that this works: tb_path_discover follows a path starting from src and src_hopid all the way to the last output port of the path 🌸 and yes, she's literally walking the whole thing.

She allocates HopIDs for the visited ports — but only if alloc_hopid is true. conditional queen. 👑

When you're done with the path, call tb_path_free to release the path and the allocated HopIDs, because leaving those lying around is not the vibe. 🧹

⚠️ okay important heads-up bestie: this function discovers also incomplete paths, so the caller should check that the dst port is the expected one. not me warning you about this, but like, check it. 🙈 if it's not the expected one, the path can be cleaned up by calling tb_path_deactivate before tb_path_free. in that order. remember the order. 🎯

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⭐ RETURN

Pointer to struct tb_path, or NULL in case of failure. if you get NULL, she's telling you it didn't work — no explanation, just vibes 💀

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🔥 SEE ALSO

• Kernel file ./drivers/thunderbolt/path.c
• tb_path_alloc(9)
• tb_path_free(9)
• tb_path_deactivate_hop(9)
• tb_path_activate(9)
• tb_path_is_invalid(9)
• tb_path_port_on_path(9)

go read them, iykyk 🍓

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🎀 that's the whole page, bestie! shoutout to ./drivers/thunderbolt for the source, and big slay energy to the October 2026 date on this one — tb_path_discover(9), periodt. 💜✨