qbman_swp_release_direct(9)

💖 qbman_swp_release_direct(9) — Kernel API Manual ✨

okay so bestie, welcome to the qbman_swp_release_direct page 💅 this is a kernel API manual situation, and we're about to learn how to issue a buffer release command. yes it's giving low-level driver energy and yes you're gonna slay it 🎀

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🌸 NAME 🌸

qbman_swp_release_direct — Issue a buffer release command 🦋

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✨ SYNOPSIS ✨

int qbman_swp_release_direct (struct qbman_swp *s , const struct
       qbman_release_desc *d , const u64 *buffers , unsigned int num_buffers );

literally the whole signature, copy it exactly, no cap 🫶

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🎀 ARGUMENTS 🎀

• s — the software portal object 💫 like, this is your main character struct, the thing doing the work
• d — the release descriptor 📋 the lil description of what you're releasing
• buffers — a pointer pointing to the buffer address to be released 📍 a pointer! pointing! at the buffer address that's getting released
• num_buffers — number of buffers to be released, must be less than 8 ⚠️ and that "must" is loud, bestie — under 8 or go home. not me stressing the boundary condition 😭

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💜 DESCRIPTION 💜

so what does it actually return? here's the vibe check:

Return 0 for success, and -EBUSY if the release command ring is not ready 😤 like the ring said "not right now, busy, try again later" — no hard feelings.

no cap: if you're getting -EBUSY, that's not a you problem, that's the ring not being ready. the return value is literally telling you the tea 💀

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🦋 SEE ALSO 🦋

the kernel file lives at ./drivers/soc/fsl/dpio/qbman-portal.c 📁 and here's the whole friend group, every single one, go say hi 🫶

qbman_swp_init(9), qbman_swp_finish(9), qbman_swp_interrupt_read_status(9), qbman_swp_interrupt_clear_status(9), qbman_swp_interrupt_get_trigger(9), qbman_swp_interrupt_set_trigger(9), qbman_swp_interrupt_get_inhibit(9), qbman_swp_interrupt_set_inhibit(9), qbman_eq_desc_set_no_orp(9), qbman_eq_desc_set_fq(9), qbman_eq_desc_set_qd(9), qbman_swp_enqueue_direct(9), qbman_swp_enqueue_mem_back(9), qbman_swp_enqueue_multiple_direct(9), qbman_swp_enqueue_multiple_mem_back(9), qbman_swp_enqueue_multiple_desc_direct(9), qbman_swp_enqueue_multiple_desc_mem_back(9), qbman_swp_push_get(9), qbman_swp_push_set(9), qbman_pull_desc_clear(9), qbman_pull_desc_set_storage(9), qbman_pull_desc_set_numframes(9), qbman_pull_desc_set_fq(9), qbman_pull_desc_set_wq(9), qbman_pull_desc_set_channel(9), qbman_swp_pull_direct(9), qbman_swp_pull_mem_back(9), qbman_swp_dqrr_next_direct(9), qbman_swp_dqrr_next_mem_back(9), qbman_swp_dqrr_consume(9), qbman_result_has_new_result(9), qbman_release_desc_clear(9), qbman_release_desc_set_bpid(9), qbman_release_desc_set_rcdi(9), qbman_swp_release_mem_back(9), qbman_swp_acquire(9), qbman_swp_set_irq_coalescing(9), qbman_swp_get_irq_coalescing(9)

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and that's the whole page, periodt 💅 this iconic little manual came from ./drivers/soc/fsl/dpio and it's dated October 2026 — screenshot it, cite it, live by it 🌈⭐ byeee 🫶