v4l2_subdev_s_stream_helper(9)

✨ v4l2_subdev_s_stream_helper 💅

okay so bestie, welcome to the Kernel API Manual 💖 this one's about a tiny little helper that does the unglamorous glue work between the new streamy world and the old-school s_stream vibe. it's short, it's sweet, and it's lowkey carrying a whole compatibility layer. let's get into it 🎀

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🌸 NAME 🌸

v4l2_subdev_s_stream_helper — the helper that implements the subdev s_stream operation by using enable_streams and disable_streams. it's giving "translator between two eras" and honestly? iconic 🫶

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⭐ SYNOPSIS ⭐

int v4l2_subdev_s_stream_helper (struct v4l2_subdev *sd , int enable );

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🦋 ARGUMENTS 🦋

• sd — the subdevice. that's your main character right there ✨
• enable — enable or disable streaming. yes, one flag for both directions, she contains multitudes 💫

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🔥 DESCRIPTION 🔥

so here's the tea ☕ — subdevice drivers that implement the streams-aware v4l2_subdev_pad_ops.enable_streams and v4l2_subdev_pad_ops.disable_streams operations can use this helper to implement the legacy v4l2_subdev_video_ops.s_stream operation. basically you already did the new hotness version, and this lil function backports it into the old API so nothing breaks. no cap, it's a whole glow-up for backwards compatibility 💅

⚠️ important bestie: this helper can only be used by subdevs that have a single source pad. one. single. source pad. if your subdev has more than one, this is not the function for you and she will not behave, periodt 🙈

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🎀 RETURN 🎀

0 on success, or a negative error code otherwise. that's it, that's the whole return value story. negative error code = something went sideways, go read your errno 🌈

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👑 SEE ALSO 👑

Kernel file ./include/media/v4l2-subdev.h — and honestly the whole extended family, here we go:

• struct v4l2_decode_vbi_line(9)
• enum v4l2_subdev_io_pin_bits(9)
• struct v4l2_subdev_io_pin_config(9)
• struct v4l2_subdev_core_ops(9)
• struct v4l2_subdev_tuner_ops(9)
• struct v4l2_subdev_audio_ops(9)
• struct v4l2_mbus_frame_desc_entry_csi2(9)
• enum v4l2_mbus_frame_desc_flags(9)
• struct v4l2_mbus_frame_desc_entry(9)
• enum v4l2_mbus_frame_desc_type(9)
• struct v4l2_mbus_frame_desc(9)
• enum v4l2_subdev_pre_streamon_flags(9)
• struct v4l2_subdev_video_ops(9)
• struct v4l2_subdev_vbi_ops(9)
• struct v4l2_subdev_sensor_ops(9)
• enum v4l2_subdev_ir_mode(9)
• struct v4l2_subdev_ir_parameters(9)
• struct v4l2_subdev_ir_ops(9)
• struct v4l2_subdev_pad_config(9)
• struct v4l2_subdev_stream_configs(9)
• struct v4l2_subdev_krouting(9)
• struct v4l2_subdev_state(9)
• struct v4l2_subdev_pad_ops(9)
• struct v4l2_subdev_ops(9)
• struct v4l2_subdev_internal_ops(9)
• struct v4l2_subdev_platform_data(9)
• struct v4l2_subdev(9)
• media_entity_to_v4l2_subdev(9)
• vdev_to_v4l2_subdev(9)
• struct v4l2_subdev_fh(9)
• to_v4l2_subdev_fh(9)
• v4l2_set_subdevdata(9)
• v4l2_get_subdevdata(9)
• v4l2_set_subdev_hostdata(9)
• v4l2_get_subdev_hostdata(9)
• v4l2_subdev_get_fwnode_pad_1_to_1(9)
• v4l2_subdev_link_validate_default(9)
• v4l2_subdev_link_validate(9)
• v4l2_subdev_has_pad_interdep(9)
• __v4l2_subdev_state_alloc(9)
• __v4l2_subdev_state_free(9)
• v4l2_subdev_init_finalize(9)
• v4l2_subdev_cleanup(9)
• v4l2_subdev_state_get_format(9)
• v4l2_subdev_state_get_crop(9)
• v4l2_subdev_state_get_compose(9)
• v4l2_subdev_state_get_interval(9)
• v4l2_subdev_get_fmt(9)
• v4l2_subdev_get_frame_interval(9)
• v4l2_subdev_set_routing(9)
• for_each_active_route(9)
• v4l2_subdev_set_routing_with_fmt(9)
• v4l2_subdev_routing_find_opposite_end(9)
• v4l2_subdev_state_get_opposite_stream_format(9)
• v4l2_subdev_state_xlate_streams(9)
• enum v4l2_subdev_routing_restriction(9)
• v4l2_subdev_routing_validate(9)
• v4l2_subdev_enable_streams(9)
• v4l2_subdev_disable_streams(9)
• __v4l2_subdev_get_frame_desc_passthrough(9)
• v4l2_subdev_get_frame_desc_passthrough(9)
• v4l2_subdev_lock_state(9)
• v4l2_subdev_unlock_state(9)
• v4l2_subdev_lock_states(9)
• v4l2_subdev_unlock_states(9)
• v4l2_subdev_get_unlocked_active_state(9)
• v4l2_subdev_get_locked_active_state(9)
• v4l2_subdev_lock_and_get_active_state(9)
• v4l2_subdev_init(9)
• v4l2_subdev_call(9)
• v4l2_subdev_call_state_active(9)
• v4l2_subdev_call_state_try(9)
• v4l2_subdev_has_op(9)
• v4l2_subdev_notify_event(9)
• v4l2_subdev_is_streaming(9)

that's the whole friend group, go say hi 💜

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and that's the page!! mwah 😘 this little manpage lives in ./include/media and it's dated October 2026 — like, future-era documentation energy fr fr. stay streaming, stay single-source-padded, and remember: negative error codes are just red flags and you deserve better 💀🌸 bye bestie 🦋