calculate_fb...l_fb_divider(9)

🌸 calculate_fb...l_fb_divider(9) — Kernel API Manual 🌸

okay bestie, welcome to the group chat that is the Kernel API Manual 💖 this one is a little baby page but she's important, so lock in. it's all about calculate_fb_and_fractional_fb_divider and honestly? the name is a mouthful but the vibe is slay ✨

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✨ NAME ✨

calculate_fb_and_fractional_fb_divider — Calculates feedback and fractional feedback dividers values 💅

like, that's literally her job. divider math. no cap.

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🦋 SYNOPSIS 🦋

bool calculate_fb_and_fractional_fb_divider (struct
       calc_pll_clock_source *calc_pll_cs , uint32_t target_pix_clk_100hz ,
       uint32_t ref_divider , uint32_t post_divider , uint32_t
       *feedback_divider_param , uint32_t *fract_feedback_divider_param );

look at her go 😭 six params, returns a bool, main character energy fr fr.

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🎀 ARGUMENTS 🎀

• calc_pll_cs — Pointer to clock source information 👑 like, the whole context bestie, you gotta hand her the source info.
• target_pix_clk_100hz — Desired frequency in 100 Hz 🌸 that's the number you actually want, but in units of 100 Hz, okay? units matter, always.
• ref_divider — Reference divider (already known) ⭐ you already figured this one out, just pass it in.
• post_divider — Post Divider (already known) 💫 same deal, you know this one already, hand it over.
• feedback_divider_param — Pointer where to store calculated feedback divider value 🫶 she writes the answer here, so give her a real place to put it.
• fract_feedback_divider_param — Pointer where to store calculated fract feedback divider value 💀 yep, the fractional one, separate pointer, separate home.

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🔥 RETURN 🔥

so here's the tea 🍓 — she fills the locations pointed by feedback_divider_param and fract_feedback_divider_param. that's the side quest.

and then it returns:

• true if feedback divider not 0 ✅ iconic, everything went great
• false should never happen) 😭 like genuinely, if you see this, something has gone deeply wrong and we need to talk about it. note the original's stray closing paren — she's quirky like that, i don't make the rules.

bestie. fr fr. if this returns false, do not just vibe past it. it "should never happen" and that's a red flag 🚩

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c — that's where she lives 🏠
• calc_fb_divider_checking_tolerance(9) — her cousin, also does divider things, go say hi 💜

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and that's the whole page bestie, short and sweet, exactly like she should be 🧚‍♀️💖

kisses, and remember: this little gem comes from ./drivers/gpu/drm/amd/display/..., dated October 2026, and yes she's still out here in the Kernel API Manual looking gorgeous 👑✨ no cap.