v4l2_m2m_poll(9)

✨ v4l2_m2m_poll(9) ✨

okay bestie, welcome to the Kernel API Manual 💅 this one's a little function from the media crew and honestly it's giving "poll but make it mem2mem" energy. let's get into it 🎀

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🌸 NAME 🌸

v4l2_m2m_poll — poll replacement, for destination buffers only 👑

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🦋 SYNOPSIS 🦋

__poll_t v4l2_m2m_poll (struct file *file , struct v4l2_m2m_ctx *m2m_ctx
, struct poll_table_struct *wait );

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💖 ARGUMENTS 💖

• file — pointer to struct file 📄 like, the file you're polling, obviously
• m2m_ctx — the m2m context assigned to the instance, handed to you by struct v4l2_m2m_ctx 🫶
• wait — pointer to struct poll_table_struct ⏳

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🔥 DESCRIPTION 🔥

so you call this from the driver's poll function, mkay? it will poll both queues 💅

here's the tea: if a buffer is available to dequeue (with dqbuf) from the source queue, this will indicate that a non-blocking write can be performed 🌈 meanwhile read will be returned in case of the destination queue. periodt.

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👑 SEE ALSO 👑

Kernel file ./include/media/v4l2-mem2mem.h — and like, the whole extended friend group 😭:

• struct v4l2_m2m_ops(9)
• struct v4l2_m2m_queue_ctx(9)
• struct v4l2_m2m_ctx(9)
• struct v4l2_m2m_buffer(9)
• v4l2_m2m_get_curr_priv(9)
• v4l2_m2m_get_vq(9)
• v4l2_m2m_try_schedule(9)
• v4l2_m2m_job_finish(9)
• v4l2_m2m_buf_done_and_job_finish(9)
• v4l2_m2m_clear_state(9)
• v4l2_m2m_mark_stopped(9)
• v4l2_m2m_dst_buf_is_last(9)
• v4l2_m2m_has_stopped(9)
• v4l2_m2m_is_last_draining_src_buf(9)
• v4l2_m2m_last_buffer_done(9)
• v4l2_m2m_suspend(9)
• v4l2_m2m_resume(9)
• v4l2_m2m_reqbufs(9)
• v4l2_m2m_querybuf(9)
• v4l2_m2m_qbuf(9)
• v4l2_m2m_dqbuf(9)
• v4l2_m2m_prepare_buf(9)
• v4l2_m2m_create_bufs(9)
• v4l2_m2m_expbuf(9)
• v4l2_m2m_streamon(9)
• v4l2_m2m_streamoff(9)
• v4l2_m2m_update_start_streaming_state(9)
• v4l2_m2m_update_stop_streaming_state(9)
• v4l2_m2m_encoder_cmd(9)
• v4l2_m2m_decoder_cmd(9)
• v4l2_m2m_mmap(9)
• v4l2_m2m_init(9)
• v4l2_m2m_release(9)
• v4l2_m2m_get(9)
• v4l2_m2m_put(9)
• v4l2_m2m_ctx_init(9)
• v4l2_m2m_ctx_release(9)
• v4l2_m2m_buf_queue(9)
• v4l2_m2m_num_src_bufs_ready(9)
• v4l2_m2m_num_dst_bufs_ready(9)
• v4l2_m2m_next_buf(9)
• v4l2_m2m_next_src_buf(9)
• v4l2_m2m_next_dst_buf(9)
• v4l2_m2m_last_buf(9)
• v4l2_m2m_last_src_buf(9)
• v4l2_m2m_last_dst_buf(9)
• v4l2_m2m_for_each_dst_buf(9)
• v4l2_m2m_for_each_src_buf(9)
• v4l2_m2m_for_each_dst_buf_safe(9)
• v4l2_m2m_for_each_src_buf_safe(9)
• v4l2_m2m_get_src_vq(9)
• v4l2_m2m_get_dst_vq(9)
• v4l2_m2m_buf_remove(9)
• v4l2_m2m_src_buf_remove(9)
• v4l2_m2m_dst_buf_remove(9)
• v4l2_m2m_buf_remove_by_buf(9)
• v4l2_m2m_src_buf_remove_by_buf(9)
• v4l2_m2m_dst_buf_remove_by_buf(9)
• v4l2_m2m_buf_copy_metadata(9)

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okay that's the whole page, bestie — go forth and poll responsibly 🫶✨

this lil cutie lives in ./include/media, dated October 2026, and it's page v4l2_m2m_poll(9) of the Kernel API Manual — mwah, sending kisses, bye 💋🎀