xhci_sideband_check(9)

💅 xhci_sideband_check(9) — a little peek into the Kernel API Manual 🎀

okay so bestie, welcome to xhci_sideband_check(9), straight out of the Kernel API Manual ✨ this one's short and sweet and honestly kind of iconic for how much it does with so little 🫶

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✨ NAME ✨

xhci_sideband_check — literally just checking whether any sidebands are out here being active 👀 no cap, that's the whole gig 💖

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🌸 SYNOPSIS 🌸

bool xhci_sideband_check (struct usb_hcd *hcd );

that's it. one argument. returns a bool. main character energy tbh 👑

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🦋 ARGUMENTS 🦋

• hcd — the host controller driver that's associated with the target host controller 🎀 like, the HCD in question, the one you're snooping on 💅

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🔥 DESCRIPTION 🔥

so the whole point: this lets other drivers — think usb controller driver vibes — check if there's any sideband activity happening on the host controller 🌈 it's giving "hey is anybody home" but for sidebands.

and why do we care?? because that info could be used for power management or other forms of resource management 💡 like, if something's active you probably don't wanna go nuking power on it, yk?

⚠️ but listen — the caller should ensure downstream usb devices are all marked as "offload_pm_locked" to ensure the correctness of the return value 🫶 this is not optional, bestie. that's a requirement for the answer to actually mean anything, fr fr 😭

and the return?? true on any active sideband existence, false otherwise 👑 simple as that, periodt.

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💜 SEE ALSO 💜

• Kernel file ./drivers/usb/host/xhci-sideband.c 📁
• xhci_sideband_notify_ep_ring_free(9)
• xhci_sideband_add_endpoint(9)
• xhci_sideband_remove_endpoint(9)
• xhci_sideband_get_endpoint_buffer(9)
• xhci_sideband_get_event_buffer(9)
• xhci_sideband_create_interrupter(9)
• xhci_sideband_remove_interrupter(9)
• xhci_sideband_interrupter_id(9)
• xhci_sideband_register(9)
• xhci_sideband_unregister(9)

like, the whole sideband friend group 🧚‍♀️ go read them all, iykyk 💖

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and that's the page!! 🍓 brought to you from ./drivers/usb/host, dated October 2026, and yeah — it's xhci_sideband_check(9) all the way down 💀✨ slay, go check those sidebands bestie 💅