__drm_ctm_3x4_to_dc_matrix(9)

💅 __drm_ctm_3x4_to_dc_matrix — the kernel API manual, bestie edition ✨

okay so real talk, this page is from the Kernel API Manual (section 9, the kernel-functions girlies) and it's about one tiny little function that does one tiny little glow-up. let me put you on 🫶

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🌸 NAME 🌸

__drm_ctm_3x4_to_dc_matrix — literally converts a DRM CTM 3x4 into a DC CSC float matrix. that's it. that's the whole job. no cap 💅

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✨ SYNOPSIS ✨

void __drm_ctm_3x4_to_dc_matrix (const struct drm_color_ctm_3x4 *ctm ,
struct fixed31_32 *matrix );

so we got a void return (no output, she just does the thing), and two args: ctm and matrix. that's the whole signature, copy it exactly bestie 🎀

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🦋 ARGUMENTS 🦋

• ctm — the DRM color transformation matrix, and she is 3x4 dimensions. that's her whole vibe. const too, so we're not touching her 🙈
• matrix — the DC CSC float matrix. this is where the output lives. it's a pointer to struct fixed31_32, so she's float-adjacent, iykyk ⭐

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🔥 DESCRIPTION 🔥

the matrix needs to be a 3x4 matrix. that's 12 entries. twelve. count 'em. if you were thinking "hmm maybe it's flexible" — no ma'am, 3x4, 12 entry, periodt 💀

like that's genuinely the entire description in the original and honestly? iconic. she says what she means and means what she says 👑

lowkey a mood that the whole DESCRIPTION is one sentence. main character energy fr fr 🌈

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👑 SEE ALSO 👑

okay this is the part where the original just lists the whole friend group, so let's give them all their moment 💖 every single one, in order, no skipping:

• the kernel file itself: ./drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c — that's where the source lives 🍓
• overview(9)
• amdgpu_dm_init_color_mod(9)
• __extract_blob_lut(9)
• __extract_blob_lut32(9)
• __is_lut_linear(9)
• __drm_lut_to_dc_gamma(9)
• __drm_lut32_to_dc_gamma(9)
• __drm_ctm_to_dc_matrix(9) — yes she has a sibling and yes the 3x4 one is the cooler one 💅
• __set_legacy_tf(9)
• __set_output_tf(9)
• __set_output_tf_32(9)
• __set_input_tf(9)
• __set_input_tf_32(9)
• amdgpu_dm_verify_lut3d_size(9)
• amdgpu_dm_verify_lut_sizes(9)
• amdgpu_dm_check_crtc_color_mgmt(9)
• amdgpu_dm_update_crtc_color_mgmt(9)
• amdgpu_dm_update_plane_color_mgmt(9)

that's the whole group chat, all 19 of them (plus the file). go say hi 🫶

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okay that's the page!! per the footer, this one's from ./drivers/gpu/drm/amd/display/... and dated October 2026, and it's __drm_ctm_3x4_to_dc_matrix(9) all over again because manpages love a callback 💜

now go convert that 3x4, bestie. slay ✨🦋🌸