pdc_rx_list_sg_add(9)

📦 version 7.3.1, in nixpkgs unstable

💖 pdc_rx_list_sg_add(9) — the Kernel API Manual glow-up 💖

okay so bestie, we're diving into pdc_rx_list_sg_add(9) from the section 9 Kernel API Manual, and honestly? she's a little workhorse and she deserves her flowers. 🌸 Let's get into it.

✨ NAME ✨

pdc_rx_list_sg_add — Add the buffers in a scatterlist to the receive descriptors for a given SPU. The caller must have already DMA mapped the scatterlist.

yes bestie, already DMA mapped. That part is on you, not on her. 💅

🦋 SYNOPSIS 🦋

int pdc_rx_list_sg_add (struct pdc_state *pdcs , struct scatterlist *sg
);

🎀 ARGUMENTS 🎀

  • pdcs — the PDC state for the SPU that will process this request. that's her whole personality, lowkey 🫶
  • sg — the scatterlist whose buffers get added to the receive ring. literally the buffers in question ✨

🌈 DESCRIPTION 🌈

okay so here's the vibe: if a receive buffer in the scatterlist is larger than PDC_DMA_BUF_MAX, then multiple receive descriptors get written — each one holding a buffer <= PDC_DMA_BUF_MAX. so she just keeps splitting until everything fits, no cap. pieces stay at or under the max, periodt 💅

🔥 RETURN 🔥

  • PDC_SUCCESS if successful 💖
  • < 0 otherwise — e.g. when the receive ring is full 😭
fair warning bestie: a negative return is not a vibe. check your ring space. 👑

🌟 SEE ALSO 🌟

Kernel file ./drivers/mailbox/bcm-pdc-mailbox.c, plus the whole friend group:

go read them, they're all iconic in their own way 🧚

and that's the page, bestie! it lives in ./drivers/mailbox, it's dated October 2026, and it's filed under pdc_rx_list_sg_add(9). slay, go add some buffers 💜🎀

📦 where this page comes from