cntl_stuck_hw_workaround(9)

💅 cntl_stuck_hw_workaround 💅

okay so bestie, welcome to the cntl_stuck_hw_workaround page from the Kernel API Manual — it's giving "niche kernel helper that saves your whole boot" energy and honestly? iconic. ✨

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🌸 NAME 🌸

cntl_stuck_hw_workaround — the workaround for an I2C engine stuck state. literally what it says on the tin, no cap. 🎀

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🦋 SYNOPSIS 🦋

void cntl_stuck_hw_workaround (struct dce_i2c_hw *dce_i2c_hw );

like, that's the whole signature. short. sweet. main character. 👑

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✨ ARGUMENTS ✨

• dce_i2c_hw — a pointer to the dce_i2c_hw structure 🫶 (yes, the param name and the struct name match, she's consistent like that)

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💖 DESCRIPTION 💖

so here's the tea, and it's kind of a mess ngl. 😭

If we boot without an HDMI display, the I2C engine does not get initialized correctly. not great, not slay, lowkey a problem. 🙈

One of its symptoms is that SW_USE_I2C does not get cleared after acquire. and then — plot twist — after setting SW_DONE_USING_I2C on release, the engine gets immediately reacquired by SW, which prevents DMUB from using it. the way it just snatches it right back?? rude. 💀

So this function does its little vibe check on the I2C arbitration status, and applies a release workaround if necessary. that's it, that's the whole job, and she ate. 🔥

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🌈 SEE ALSO 🌈

Kernel file ./drivers/gpu/drm/amd/display/dc/dce/dce_i2c_hw.c — go read her, she's right there 👀📖

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mwah 💋 that's the page! this little icon lives over in ./drivers/gpu/drm/amd/display/... and this version is dated October 2026, tagged cntl_stuck_hw_workaround(9) — catch you in the next one bestie, stay hydrated and keep your arbitration status checked 🧚💜