__drm_writeb...nnector_init(9)

💅 __drm_writeback_connector_init(9) — from the Kernel API Manual, bestie ✨

okay so picture this: it's giving kernel-internal, it's giving writeback connectors, and you found the double-underscore version (iykyk 👀). This is the one where you bring your own encoder. Let's get into it 🎀

---

🌸 NAME 🌸

__drm_writeback_connector_init — initialize a writeback connector with a custom encoder 💖

---

✨ SYNOPSIS ✨

int __drm_writeback_connector_init (struct drm_device *dev,
                                    struct drm_writeback_connector *wb_connector,
                                    struct drm_encoder *enc,
                                    const u32 *formats,
                                    int n_formats);

---

🫶 ARGUMENTS 🫶

• dev — the DRM device, the main character of this whole story 🌈
• wb_connector — the writeback connector you're initializing. yes, that one. her. 👑
• enc — a handle to the already initialized drm encoder (key word: already — more on this in a sec 😭)
• formats — an array of the supported pixel formats for the writeback engine 🎨
• n_formats — the length of the formats array. literally just how many there are, no cap 🔢

---

💜 DESCRIPTION 💜

so what does this function actually do? glad you asked 💅

It creates the writeback-connector-specific properties — but only if they haven't already been created (she's not gonna duplicate them, she's better than that ✨). Then it initializes the connector as type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property values. slay.

⚠️ important vibe check: this function assumes that the drm_writeback_connector's encoder has already been created and initialized before you invoke this function. Like, that's your job, not hers. don't come in here with an un-initialized encoder, bestie 🙈

In addition — and yes there's more — this function also assumes that callers of this API will manage assigning the encoder helper functions, possible_crtcs, and any other encoder-specific operation. So that's on you too. main character responsibility fr fr 💀

---

🔥 RETURN 🔥

0 on success, or a negative error code 😭 — so basically, check it. don't ignore the return value. she's telling you something.

---

🦋 SEE ALSO 🦋

• Kernel file ./drivers/gpu/drm/drm_writeback.c overview(9)
• drm_writeback_connector_init(9)
• drm_writeback_connector_init_with_encoder(9)
• drm_writeback_connector_cleanup(9) — yes you will need this one eventually 🧚
• drmm_writeback_connector_init(9)
• drm_writeback_queue_job(9)
• drm_writeback_signal_completion(9)

---

okay that's the whole page, you ate that 💅✨ go forth and initialize your writeback connectors responsibly, bestie 🫶💖

🎀 sign-off time: this icon of a manual page lives under ./drivers/gpu/drm and is dated October 2026 — periodt. 🌸💜