__intel_wait..._register_fw(9)

💖 NAME 💖

okay so bestie, this is the __intel_wait..._register_fw(9) page from the Kernel API Manual — and the function is literally __intel_wait_for_register_fw, which waits until register matches expected state ✨. no cap, that’s the whole vibe.

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✨ SYNOPSIS ✨

int __intel_wait_for_register_fw (struct intel_uncore *uncore , i915_reg_t reg , u32 mask , u32 value , unsigned int fast_timeout_us , unsigned int slow_timeout_ms , u32 *out_value );

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🎀 ARGUMENTS 🎀

• uncore — the struct intel_uncore 🫶
• reg — the register to read 👑
• mask — mask to apply to register value 🎀
• value — expected value ⭐
• fast_timeout_us — fast timeout in microsecond for atomic/tight wait 🔥
• slow_timeout_ms — slow timeout in millisecond 🌸
• out_value — optional placeholder to hold registry value 💅

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🦋 DESCRIPTION 🦋

This routine waits until the target register reg contains the expected value after applying the mask, i.e. it waits until:

(intel_uncore_read_fw(uncore, reg) & mask) == value

Otherwise, the wait will timeout after slow_timeout_ms milliseconds. ⏳

For atomic context slow_timeout_ms must be zero and fast_timeout_us must be not larger than 20,0000 microseconds. 😭 this part is serious, fr fr.

Note that this routine assumes the caller holds forcewake asserted, it is not suitable for very long waits. See intel_wait_for_register if you wish to wait without holding forcewake for the duration (i.e. you expect the wait to be slow). 🧚

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🌸 RETURN 🌸

0 if the register matches the desired condition, or -ETIMEDOUT. 💀

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💅 SEE ALSO 💅

Kernel file ./drivers/gpu/drm/i915/intel_uncore.c 📁

• intel_uncore_forcewake_get(9)
• intel_uncore_forcewake_user_get(9)
• intel_uncore_forcewake_user_put(9)
• intel_uncore_forcewake_get__locked(9)
• intel_uncore_forcewake_put(9)
• intel_uncore_forcewake_flush(9)
• intel_uncore_forcewake_put__locked(9)
• __intel_wait_for_register(9)
• intel_uncore_forcewake_for_reg(9)

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xoxo, your Unix bestie 💖 — this page is from ./drivers/gpu/drm/i915, October 2026 edition 🎀✨