rio_add_outb_message(9)

💌 rio_add_outb_message(9) — the kernel API manual, bestie edition

ok so this is a page from the Kernel API Manual about rio_add_outb_message(9) and honestly? it's giving "small function, big responsibility." let's get into it 🫶

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✨ NAME ✨

rio_add_outb_message — literally just: add a RIO message to an outbound mailbox queue. that's the whole vibe. no cap. 💅

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🌸 SYNOPSIS 🌸

int rio_add_outb_message (struct rio_mport *mport , struct rio_dev *rdev
, int mbox , void *buffer , size_t len );

it returns an int, bestie. keep that in mind. 👑

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🎀 ARGUMENTS 🎀

• mport — the RIO master port that contains the outbound queue. it's the one holding the queue, like the friend who's holding everyone's stuff at the concert 🎒
• rdev — the RIO device the message is be sent to. yes, the original says "is be sent to" and we're keeping it, iconic grammar moment 😭
• mbox — the outbound mailbox queue. this specific one. pick your queue wisely ✨
• buffer — pointer to the message buffer. the actual message lives here 📨
• len — length of the message buffer. how big is the message? that's this. 📏

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🦋 DESCRIPTION 🦋

okay so the whole thing in one breath: it adds a RIO message buffer to an outbound mailbox queue for transmission. 📤

and then it returns 0 on success. that's it. zero means slay. 🎉

lowkey the shortest description ever, but that's because the function knows exactly what it is. main character energy fr fr. 💜

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💜 SEE ALSO 💜

the whole friend group, no one left out 🫶:

• Kernel file ./include/linux/rio_drv.h
• rio_local_read_config_32(9)
• rio_local_write_config_32(9)
• rio_local_read_config_16(9)
• rio_local_write_config_16(9)
• rio_local_read_config_8(9)
• rio_local_write_config_8(9)
• rio_read_config_32(9)
• rio_write_config_32(9)
• rio_read_config_16(9)
• rio_write_config_16(9)
• rio_read_config_8(9)
• rio_write_config_8(9)
• rio_send_doorbell(9)
• rio_init_mbox_res(9)
• rio_init_dbell_res(9)
• RIO_DEVICE(9)
• rio_add_inb_buffer(9)
• rio_get_inb_message(9)
• rio_name(9)
• rio_get_drvdata(9)
• rio_set_drvdata(9)

like, the entire config-reading family plus the mailbox and doorbell crew plus the driver-data besties. iykyk 🌈

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🧚 sign-off 🧚

this page lives in ./include/linux, dated October 2026, and it's rio_add_outb_message(9) in the Kernel API Manual. go add that outbound message, bestie — and remember: 0 on success, always. 💖✨🎀