STRUCT DC_CRTC(9)

💅 struct dc_crtc(9) — the kernel API manual, but make it make sense

okay so this is a page from the Kernel API Manual, all about struct dc_crtc. it lives in ./drivers/gpu/drm/imx/dc and it's dated October 2026, bestie. let's get into it 🎀

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✨ NAME ✨

struct dc_crtc — the DC-specific drm_crtc. that's it, that's the vibe. it's the display-controller-side glow-up of a regular drm_crtc 👑

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🌸 SYNOPSIS 🌸

here's the whole struct, verbatim, no cap:

struct dc_crtc {
    struct drm_crtc base;
    struct dc_de *de;
    struct dc_cf *cf_cont;
    struct dc_cf *cf_safe;
    struct dc_ed *ed_cont;
    struct dc_ed *ed_safe;
    struct dc_fg *fg;
    unsigned int irq_dec_framecomplete;
    unsigned int irq_dec_seqcomplete;
    unsigned int irq_dec_shdload;
    unsigned int irq_ed_cont_shdload;
    unsigned int irq_ed_safe_shdload;
    struct completion dec_seqcomplete_done;
    struct completion dec_shdload_done;
    struct completion ed_cont_shdload_done;
    struct completion ed_safe_shdload_done;
    struct drm_pending_vblank_event *event;
    struct dc_crtc_irq irqs[DC_CRTC_IRQS];
};

like, look at her. so many fields. so structured. main character energy fr fr 💖

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🦋 Members 🦋

okay let's go field by field, don't skip, every single one matters:

• base — the base drm_crtc structure. the foundation, the roots, the blueprint 🫶
• de — display engine. the whole engine, iconic.
• cf_cont — the content stream constframe.
• cf_safe — the safety stream constframe.
• ed_cont — the content stream extdst.
• ed_safe — the safety stream extdst.
• fg — framegen. yes bestie, framegen 💫
• irq_dec_framecomplete — display engine configuration frame complete interrupt.
• irq_dec_seqcomplete — display engine configuration sequence complete interrupt.
• irq_dec_shdload — display engine configuration shadow load interrupt.
• irq_ed_cont_shdload — content stream extdst shadow load interrupt.
• irq_ed_safe_shdload — safety stream extdst shadow load interrupt.
• dec_seqcomplete_done — display engine configuration sequence completion.
• dec_shdload_done — display engine configuration shadow load completion.
• ed_cont_shdload_done — content stream extdst shadow load completion.
• ed_safe_shdload_done — safety stream extdst shadow load completion.
• event — cached pending vblank event. it's been waiting for this moment ✨
• irqs — the interrupt list. the whole squad, lowkey 🔥

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💜 Description 💜

so. each display controller contains one content stream and one safety stream. in general, the two streams have the same functionality — twins, basically 👯

one stream is overlaid on the other by fg. and this driver makes a very specific choice: it chooses to generate black constant color from the content stream as background color, builds plane(s) on the content stream by using layerblend(s), and always generates a constant color from the safety stream. the way that's a whole design philosophy 😭

note (and this is the good part): due to the decoupled timing, the safety stream still works to show the constant color properly even when the content stream has completely hung up due to mal-function of this driver. so when everything is on fire, the safety stream is still standing there serving looks. bestie is resilient. 💅

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/imx/dc/dc-kms.h
• struct dc_plane(9)

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and that's the page! 🎀 source/version & date tea: this one comes from ./drivers/gpu/drm/imx/dc, dated October 2026. go forth and read your structs, babe, you got this 💖✨🌸