nand_subop_...ta_start_off(9)

📦 version 7.3.1, in nixpkgs unstable

💅 nand_subop_get_data_start_off — Kernel API Manual energy ✨

okay so bestie, we're diving into the Kernel API Manual today and the page we're on is nand_subop_...ta_start_off(9) (yes the title's doing that truncated little thing, we love a mysterious queen 🎀). Strap in, this one's short but it's important.

🌸 NAME 🌸

nand_subop_get_data_start_off — literally just: get the start offset in a data array. That's the whole gig. She's focused. She's not doing extra. 👑

✨ SYNOPSIS ✨

unsigned int nand_subop_get_data_start_off (const struct nand_subop
*subop , unsigned int instr_idx );

that's it, that's the whole signature, no notes. 💖

🦋 ARGUMENTS 🦋

  • subop — the entire sub-operation. the whole vibe, the whole context, the entire sub-operation, we're passing all of it in.
  • instr_idx — the index of the instruction inside the sub-operation. basically: which instruction are we talking about, and it's a number, and it's an unsigned int, periodt.

🔥 DESCRIPTION 🔥

so here's the tea ☕ — during driver development, one could be tempted to directly use the ->data->buf.{in,out} field of data instructions. and bestie, i have to say this clearly: this is wrong. 🚫 not me catching you trying to skip the abstraction. data instructions might be split. like, they get broken up. they go their separate ways. so that direct field access? not it. 🙈

what you do instead: give this function a data instruction, and it returns the offset to start from. that's it. it hands you the starting point so you're indexing into the right slice of the data array instead of confidently reading the wrong bytes. iconic behavior honestly. 👑

fr fr, do not go poking at ->data->buf.{in,out} directly. split data instructions will humble you so fast. 😭

💜 SEE ALSO 💜

a lot of friends on this list, and yes we're naming every single one of them because nobody gets left out of the group chat 🫶. also note the kernel file: ./drivers/mtd/nand/raw/nand_base.c

like i said. everyone. 🌈 a whole friend group of NAND functions and they all showed up to the party.

🌟 little sign-off from the footer, because it deserves a mention: this page lives under ./drivers/mtd/nand/raw, it's dated October 2026, and yes, the version line still calls it nand_subop_...ta_start_off(9). she's consistent, she's mysterious, we stan. mwah 💋✨
📦 where this page comes from