STRUCT RING_DESC(9)

💖 NAME 💖

okay so, welcome to the Kernel API Manual page for struct ring_desc(9), bestie — manual name folded in right here near the top, no cap. The NAME vibe is:

struct ring_desc — TX/RX ring entry. Slay. 💅

✨ SYNOPSIS ✨

Here’s the struct in all its exact, character-for-character glory:

       struct ring_desc {
           u64 phys;
           u32 length:12;
           u32 eof:4;
           u32 sof:4;
           enum ring_desc_flags flags:12;
           u32 time;
        };

🎀 Members 🎀

• phys — DMA mapped address of the frame. Lowkey important. 📍
• length — Size of the ring. She’s giving capacity. 📏
• eof — End of frame protocol defined field. Bye bestie, frame’s over. 🏁
• sof — Start of frame protocol defined field. Hiiii, frame’s starting. 🌟
• flags — Ring descriptor flags. Iconic little flag energy. 🚩
• time — Fill with zero. That’s the instruction, periodt. 0️⃣

🦋 Description 🦋

For TX, set length/eof/sof. For RX, length/eof/sof are set by the NHI. That’s the whole tea, fr fr. 🫖

🌈 SEE ALSO 🌈

• Kernel file ./drivers/thunderbolt/nhi_regs.h
• enum icl_lc_mailbox_cmd(9)

okay bestie, that’s a wrap 🫶 Signing off from ./drivers/thunderbolt, dated October 2026, on the struct ring_desc(9) page. Mwah 💋✨