ssam_ctrl_notif_d0_entry(9)

✨ ssam_ctrl_notif_d0_entry ✨

okay so bestie, welcome to the Kernel API Manual 🎀 — this one's a lil deep-cut from the Surface aggregator world, and yes it's a (9) page, so grab a strawberry drink and let's go 🍓

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🌸 NAME 🌸

ssam_ctrl_notif_d0_entry — the function that's literally just telling the EC "hey girl, we're back, we're in D0 now" 💅

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🦋 SYNOPSIS 🦋

int ssam_ctrl_notif_d0_entry (struct ssam_controller *ctrl );

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💜 ARGUMENTS 💜

• ctrl — the controller. the one and only. your main character controller 👑

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🔥 DESCRIPTION 🔥

so what this does is it notifies the EC that the driver has exited a lower-power state and has entered the D0 power state. like a "we're so back" text to the embedded controller 🫶

and okay, being so fr fr right now: the exact effects of this function related to the EC are currently unknown. nobody's out here documenting the vibe. it's giving mystery. 🔮

the way this works is — this function will only send the D0-entry notification command if D0-state notifications are supported by the EC. so if the EC isn't about that life, nothing gets sent. and heads up: only newer Surface generations support these notifications 💀 older ones are just not in the group chat.

for more details, go see ssam_ctrl_notif_d0_exit — that's the sister function, iykyk 🌈

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⭐ RETURN ⭐

here's the vibe check on what you get back:

• returns zero on success — or also if no request has been executed at all (nothing to do, no notes)
• the status of the executed SAM request if that request failed 😭
• or -EPROTO if an unexpected response has been received 🙈

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🧚 SEE ALSO 🧚

the kernel file in question, iconic:

• ./drivers/platform/surface/aggregator/controller.c

and the whole extended fam, no cap, every single one:

• ssh_seq_reset(9), ssh_seq_next(9), ssh_rqid_reset(9), ssh_rqid_next(9), ssam_event_matches_notifier(9), ssam_nfblk_call_chain(9), ssam_nfblk_insert(9), ssam_nfblk_find(9), ssam_nfblk_remove(9), ssam_nf_head_init(9), ssam_nf_head_destroy(9)
• struct ssam_nf_refcount_key(9), struct ssam_nf_refcount_entry(9), ssam_nf_refcount_inc(9), ssam_nf_refcount_dec(9), ssam_nf_refcount_dec_free(9), ssam_nf_refcount_empty(9), ssam_nf_call(9), ssam_nf_init(9), ssam_nf_destroy(9)
• ssam_event_item_cache_init(9), ssam_event_item_cache_destroy(9), ssam_event_item_free(9), ssam_event_item_alloc(9), ssam_event_queue_push(9), ssam_event_queue_pop(9), ssam_event_queue_is_empty(9), ssam_cplt_get_event_queue(9), ssam_cplt_submit(9), ssam_cplt_submit_event(9), ssam_cplt_flush(9), ssam_event_queue_init(9), ssam_cplt_init(9), ssam_cplt_destroy(9)
• ssam_controller_device(9), ssam_controller_get(9), ssam_controller_put(9), ssam_controller_statelock(9), ssam_controller_stateunlock(9), ssam_controller_lock(9), ssam_controller_caps_load_from_acpi(9), ssam_controller_caps_load_from_of(9), ssam_controller_caps_load(9), ssam_controller_init(9), ssam_controller_start(9), ssam_controller_shutdown(9), ssam_controller_destroy(9), ssam_controller_suspend(9), ssam_controller_resume(9)
• ssam_request_write_data(9), ssam_request_sync_alloc(9), ssam_request_sync_free(9), ssam_request_sync_init(9), ssam_request_sync_submit(9), ssam_request_do_sync(9), ssam_request_do_sync_with_buffer(9), struct ssh_notification_params(9), ssam_ssh_event_enable(9), ssam_ssh_event_disable(9), ssam_get_firmware_version(9), ssam_ctrl_notif_display_off(9), ssam_ctrl_notif_display_on(9), ssam_ctrl_notif_d0_exit(9)
• ssam_nf_refcount_enable(9), ssam_nf_refcount_disable_free(9), ssam_notifier_register(9), __ssam_notifier_unregister(9), ssam_controller_event_enable(9), ssam_controller_event_disable(9), ssam_notifier_disable_registered(9), ssam_notifier_restore_registered(9), ssam_notifier_is_empty(9), ssam_notifier_unregister_all(9)
• ssam_irq_setup(9), ssam_irq_free(9), ssam_irq_arm_for_wakeup(9), ssam_irq_disarm_wakeup(9)

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ok and before you close the tab — small note on how this doc came to be: it's sourced from ./drivers/platform/surface/agg..., from October 2026. mark it in your calendar bestie 📅✨

slay, go notify that EC. you ate 💅👑🌸