pcc_send_data(9)

💖 NAME 💖

okay so bestie, welcome to pcc_send_data(9) from the Kernel API Manual — the function is literally pcc_send_data, and it’s called from Mailbox Controller code. Here it is used only to ring the channel doorbell. The PCC client specific read/write is done in the client driver in order to maintain atomicity over PCC channel once OS has control over it. See above for flow of operations. (yes, it really says “See above” — love that for us 👆✨)

✨ SYNOPSIS ✨

the whole signature, no crumbs:

int pcc_send_data (struct mbox_chan *chan , void *data );

🎀 ARGUMENTS 🎀

• chan — pointer to the Mailbox channel over which to send data. That’s the specific channel getting the send 💌
• data — client specific data written over channel. Used here only for debug after PCC transaction completes. So it’s not the main read/write star here; it’s debug fuel after the transaction wraps 🐛✨

💅 RETURN 💅

Err if something failed, else 0 for success. Simple, iconic, no cap 👑

🦋 SEE ALSO 🦋

the kernel file ./drivers/mailbox/pcc.c is the home base, and these are the linked cuties: struct pcc_chan_reg(9), struct pcc_chan_info(9), pcc_map_interrupt(9), pcc_mbox_irq(9), pcc_mbox_request_channel(9), pcc_mbox_free_channel(9), pcc_startup(9), pcc_shutdown(9), parse_pcc_subspace(9), pcc_parse_subspace_irq(9), pcc_parse_subspace_db_reg(9), pcc_parse_subspace_shmem(9), acpi_pcc_probe(9), pcc_mbox_probe(9) 🌈

and that’s the vibe! this page is sourced from ./drivers/mailbox, dated October 2026 — mwah 💋🫶