radeon_atpx_switch_start(9)

📦 version 7.3.1, in nixpkgs unstable

💖 NAME 💖

radeon_atpx_switch_start — bestie, this is the lil heads-up that tells the sbios a GPU switch is about to go down 👀✨

Ok so real talk, this page is from the Kernel API Manual (the radeon_atpx_switch_start(9) one, iykyk) and it's genuinely iconic — it's the function that slides into the firmware's DMs and is like "hey girl, we're switching GPUs, don't panic 💅"

✨ SYNOPSIS ✨

int radeon_atpx_switch_start (struct radeon_atpx *atpx , u16 mux_id );

That's it, that's the whole vibe check 🫶

🎀 ARGUMENTS 🎀

  • atpx — the atpx info struct 🌸 this is literally the little info packet you're handing over, no cap
  • mux_id — the mux state, and the numbers matter so listen up 👑: 0 = integrated GPU, 1 = discrete GPU

💅 DESCRIPTION 💅

So what does it actually do? It executes the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION ATPX function — yes that's a whole mouthful, the ATPX girlies really said "make it long" 😭 — to notify the sbios that a switch between the discrete GPU and integrated GPU has begun 🔥

And bestie, this applies to all asics. Every single one. No exceptions, periodt 🧚

It returns 0 on success, and an error on failure 💀 so like, check your return value, fr fr. Don't be out here ignoring it 🙈

Warning-ish reminder from your girl: nonzero return = something went wrong, mmkay? Not me letting that slide 🍓

🦋 SEE ALSO 🦋

The kernel file lives right here, bookmark it:

./drivers/gpu/drm/radeon/radeon_atpx_handler.c

And the whole ATPX friend group 🫶 — they all show up to the group chat:

⭐ Sign-off ⭐

You've reached the end bestie, slay 💖 This one came out of ./drivers/gpu/drm/radeon and it's dated October 2026 ⭐ so you know it's fresh. Go forth and notify that sbios, main character energy only 👑🌈💜

📦 where this page comes from