mmc_hw_reset(9)

📦 version 7.3.1, in nixpkgs unstable

💅 mmc_hw_reset — like, the kernel API manual page, bestie ✨

okay so we're doing mmc_hw_reset(9) today, straight out of the Kernel API Manual. it's a whole function. it resets a card. in hardware. that's the tweet. now let me actually tell you the details 🎀

✨ NAME ✨

mmc_hw_reset — reset the card in hardware 🔥

like. physically. in the silicon. not a vibe reset, a hardware reset.

🌸 SYNOPSIS 🌸

int mmc_hw_reset (struct mmc_card *card );

she takes one argument and returns an int, periodt 💅

🦋 ARGUMENTS 🦋

  • card — the card to be reset 🃏 like, the actual struct mmc_card * you want to yeet back into a known state.

💖 DESCRIPTION 💖

Hard reset the card. that's it, that's the whole bit ✨

so the way that this works: this function is only for upper layers, like the block layer or card drivers. iykyk 👑

🚨 you CANNOT use it in host drivers — struct mmc_card might be gone by then. like, literally gone. not me calling a function on a freed pointer 😭💀 that's undefined-behaviour o'clock and we are NOT going there.

🌈 RETURN 🌈

  • 0 on success 🎉 slay, the card got reset
  • -errno on failure 😭 the classic negative-errno situation, go check that errno bestie

👑 SEE ALSO 👑

kernel file ./drivers/mmc/core/core.c — and while you're there, go check out all of these:

that's the whole reading list, bestie, no skimming 🫶

mwah 💋 this page lives in ./drivers/mmc/core, dated October 2026, and it's mmc_hw_reset(9) — go reset something responsibly 🧚‍♀️✨

📦 where this page comes from