radeon_compute_pll_avivo(9)

💅 NAME 💅

radeon_compute_pll_avivo — okay so this one computes PLL paramaters ✨ (that's how the manpage spells it and I'm not fixing it, not my job 💀)

This is a Kernel API Manual situation, so like… kernel-adjacent, iykyk 🧚

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✨ SYNOPSIS ✨

void radeon_compute_pll_avivo (struct radeon_pll *pll , u32 freq , u32
       *dot_clock_p , u32 *fb_div_p , u32 *frac_fb_div_p , u32 *ref_div_p , u32
       *post_div_p );

yes bestie it takes seven args and most of them are pointers, stay with me 🫶

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🎀 ARGUMENTS 🎀

• pll — the info about the PLL, like its whole little personality ✨
• freq — the target frequency we're aiming for 🎯
• dot_clock_p — where the resulting pixel clock comes out 💖
• fb_div_p — where the resulting feedback divider comes out 🔥
• frac_fb_div_p — the fractional part of the feedback divider, the spicy decimal bit 🌸
• ref_div_p — resulting reference divider 👑
• post_div_p — resulting reference divider (no that's not a typo on my end, that's literally what the original says — both of these say "resulting reference divider", and I'm just the messenger 🫡)

heads up: the last two arguments have identical descriptions in the source. I'm not gonna invent a difference that isn't there, that's not the vibe 🙈

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🔥 DESCRIPTION 🔥

So the whole goal here? Try to calculate the PLL parameters to generate the given frequency 💅

And the formula it's working with is literally this:

dot_clock = (ref_freq * feedback_div) / (ref_div * post_div)

that's it, that's the math, and honestly? she ate 👑

no cap, the function is trying to work out those PLL parameters for the frequency you hand it — that's the assignment, that's the whole mission 💖

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🦋 SEE ALSO 🦋

Kernel file: ./drivers/gpu/drm/radeon/radeon_display.c

and the friend group 💜:

• radeon_unpin_work_func(9)
• radeon_crtc_handle_flip(9)
• radeon_flip_work_func(9)
• avivo_reduce_ratio(9)
• avivo_get_fb_ref_div(9)

go read those too, they're all lowkey relevant, fr fr 🌈

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and that's the whole page bestie ✨ source is ./drivers/gpu/drm/radeon, dated October 2026, and it's the radeon_compute_pll_avivo(9) manual page — periodt 💅🎀🦋