ipc_pm_signal_hpda_doorbell(9)

💅 ipc_pm_signal_hpda_doorbell — a little kernel function with main character energy

okay so this is a page straight out of the Kernel API Manual, and it's about one (1) function that wakes your device up and pokes the head pointer update interrupt. bestie, it's giving "small function, big responsibility." 💖

✨ NAME ✨

ipc_pm_signal_hpda_doorbell — literally wakes the device up if it's chilling in low power mode, and triggers a head pointer update interrupt. that's the whole vibe. 🦋

🌸 SYNOPSIS 🌸

void ipc_pm_signal_hpda_doorbell (struct iosm_pm *ipc_pm , u32
identifier , bool host_slp_check );

no return value, no drama, just vibes and a void. periodt. 💅

🎀 ARGUMENTS 🎀

• ipc_pm — a pointer to the power management component. like, the whole pm situation, handed to you. 🫶
• identifier — tells you what component triggered the hpda update irq. iykyk. 🔥
• host_slp_check — okay so this one's the main character of the arguments ngl:
  • if it's set to true, then the Host Sleep state machine check gets performed. and like — if the Host Sleep state machine allows HP update, then only the doorbell is triggered. otherwise the pending flag gets set. 🙈
  • if it's set to false, then the Host Sleep check is not performed. this is lowkey helpful for Host Sleep negotiation through the message ring. ✨

🦋 SEE ALSO 🦋

kernel file ./drivers/net/wwan/iosm/iosm_ipc_pm.h — plus the whole friend group:

• union ipc_pm_cond(9)
• enum ipc_mem_host_pm_state(9)
• enum ipc_mem_dev_pm_state(9)
• struct iosm_pm(9)
• enum ipc_pm_unit(9)
• ipc_pm_init(9)
• ipc_pm_deinit(9)
• ipc_pm_dev_slp_notification(9)
• ipc_pm_set_s2idle_sleep(9)
• ipc_pm_prepare_host_sleep(9)
• ipc_pm_prepare_host_active(9)
• ipc_pm_wait_for_device_active(9)
• ipc_pm_trigger(9)

and that's the page!! 🎀 this masterpiece lives over at ./drivers/net/wwan/iosm, it's dated October 2026, and it goes by ipc_pm_signal_hpda_doorbell(9). go drink some water and read your kernel source, bestie 💜🌷✨