coresight_timeout_etm(9)

💖 NAME 💖

okay bestie, welcome to coresight_timeout_etm(9) from the Kernel API Manual — yes, we are literally in the kernel API group chat now 💅

coresight_timeout_etm — loop until a bit has changed to a specific state. no cap, that’s the whole vibe ✨

---

🌸 SYNOPSIS 🌸

int coresight_timeout_etm (struct etm_drvdata *drvdata , u32 offset ,
       int position , int value );

---

🎀 ARGUMENTS 🎀

• drvdata — etm’s private data structure. it’s giving “main character data holder” energy 🫶
• offset — address of a register, starting from addr.
• position — the position of the bit of interest. yes, that bit 👀
• value — the value the bit should have. we’re manifesting this exact state ✨

---

🦋 DESCRIPTION 🦋

okay so this is basically the same as coresight_timeout, except for the register access method where we have to account for CP14 configurations. lowkey important, highkey specific 💜

---

🌈 RETURN 🌈

returns 0 as soon as the bit has taken the desired state, or -EAGAIN if TIMEOUT_US has elapsed — which ever happens first. periodt 💅

---

🔥 SEE ALSO 🔥

• Kernel file ./drivers/hwtracing/coresight/coresight-etm3x-core.c — go read it, bestie, iykyk 📖✨

---

mwah 💋 this iconic little page comes from the ./drivers/hwtracing/coresight source/version and is dated October 2026. coresight_timeout_etm(9) out! 🫶🎀