vpdma_update_dma_addr(9)

💅 vpdma_update_dma_addr(9) — the Kernel API Manual glow-up 🎀

okay so bestie, this one lives in the Kernel API Manual and it's genuinely one of those "small function, big main character energy" situations. let's get into it ✨

---

🌸 NAME 🌸

vpdma_update_dma_addr — update the DMA address in a descriptor. that's it, that's the vibe 🦋

---

✨ SYNOPSIS ✨

void vpdma_update_dma_addr (struct vpdma_data *vpdma , struct
       vpdma_desc_list *list , dma_addr_t dma_addr , void *write_dtd , int drop
       , int idx );

no return value, it's a void, she simply does the thing and leaves 💅

---

🫶 ARGUMENTS 🫶

• vpdma — the VPDMA device context. like, the whole situation she's working inside 🎀
• list — the vpdma_desc_list we're adding this descriptor to. the guest list, basically 🌸
• dma_addr — the new DMA address getting programmed into the descriptor. the fresh new number ⭐
• write_dtd — descriptor pointer, used to compute the write-back address. it's giving "math but make it pointers" 😭
• drop — if true, set the drop bit in the write descriptor. yes, a literal drop bit, we love a dramatic queen 💀
• idx — index of the descriptor in the list to update. which one? this one 👑
• list — (already said her, she's that important) 😌

---

💖 DESCRIPTION 💖

So what she actually does: she updates the dma addresses of the descriptor at idx in list. that's the whole assignment 🔥

and why is that iconic? because it lets you reuse an existing descriptor list with a new buffer address instead of rebuilding the entire list from scratch — which is literally needed when multiple clients share the same VPDMA engine. no cap, teamwork makes the dream work 🫶

one thing to keep in your notes app tho, bestie: the list buffer is unmapped before the update and remapped after 🙈 like she literally takes it off and puts it back on. so don't be out here assuming the mapping is just sitting there untouched the whole time, ok? 😭

---

🔍 SEE ALSO 🔍

• Kernel file ./drivers/media/platform/ti/vpe/vpdma.c — go read the source, iykyk 📖💜

---

ngl this is a short one but she's lowkey carrying a whole shared-engine workflow on her shoulders. respect the process ✨

---

and that's the page, bestie!! 🎀 this lil beauty ships from ./drivers/media/platform/ti/vpe and the date on it is October 2026 — so yeah, she's from the future, obviously 💅🦋 mwah, go update some descriptors responsibly 💖