si_calc_upll_dividers(9)

💅 si_calc_upll_dividers(9) 💅

okay so welcome to the Kernel API Manual, bestie!! this is the page for si_calc_upll_dividers(9), and it's giving "math but make it clock dividers" ✨. no cap, we're keeping every single detail.

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🌸 NAME 🌸

si_calc_upll_dividers — calc UPLL clock dividers 💖

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💖 SYNOPSIS 💖

int si_calc_upll_dividers (struct amdgpu_device *adev , unsigned vclk ,
       unsigned dclk , unsigned vco_min , unsigned vco_max , unsigned fb_factor
       , unsigned fb_mask , unsigned pd_min , unsigned pd_max , unsigned
       pd_even , unsigned *optimal_fb_div , unsigned *optimal_vclk_div ,
       unsigned *optimal_dclk_div );

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✨ ARGUMENTS ✨

okay bestie, here's the whole cast — every single one matters 🫶

• adev — amdgpu_device pointer
• vclk — wanted VCLK
• dclk — wanted DCLK
• vco_min — minimum VCO frequency
• vco_max — maximum VCO frequency
• fb_factor — factor to multiply vco freq with
• fb_mask — limit and bitmask for feedback divider
• pd_min — post divider minimum
• pd_max — post divider maximum
• pd_even — post divider must be even above this value
• optimal_fb_div — resulting feedback divider
• optimal_vclk_div — resulting vclk post divider
• optimal_dclk_div — resulting dclk post divider

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🦋 DESCRIPTION 🦋

So like, this function calculates dividers for UVDs UPLL (except APUs) 💅. It returns zero on success; -EINVAL on error. That's the whole vibe check, no cap.

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🎀 SEE ALSO 🎀

Kernel file ./drivers/gpu/drm/amd/amdgpu/si.c — go peek if you're nosy, iykyk 👀

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source/version: ./drivers/gpu/drm/amd/amdgpu • date: October 2026 • si_calc_upll_dividers(9) — byeee bestie!! 💜