usb_acpi_port_lpm_incapable(9)

💖 usb_acpi_port_lpm_incapable(9) — Kernel API Manual ✨

📛 NAME

usb_acpi_port_lpm_incapable — check if lpm should be disabled for a port. 🫶

🛠️ SYNOPSIS

int usb_acpi_port_lpm_incapable (struct usb_device *hdev , int index );

Copy it exactly, bestie — spaces and all 💅

🎀 ARGUMENTS

• hdev — USB device belonging to the usb hub 🫶
• index — zero based port index 🔢

🧠 DESCRIPTION

Okay so here’s the tea: Some USB3 ports may not support USB3 link power management U1/U2 states due to different retimer setup. ACPI provides _DSM method which returns 0x01 if U1 and U2 states should be disabled. Evaluate _DSM with:

• Arg0: UUID = ce2ee385-00e6-48cb-9f05-2edb927c4899
• Arg1: Revision ID = 0
• Arg2: Function Index = 5
• Arg3: (empty)

Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0. Periodt. 💅

👀 SEE ALSO

Kernel file ./drivers/usb/core/usb-acpi.c — go peek, bestie 🌸 And the squad: usb_acpi_power_manageable(9), usb_acpi_set_power_state(9), usb_acpi_add_usb4_devlink(9). 💅

That’s the whole page, bestie 💖 Source/version: ./drivers/usb/core · Date: October 2026 · Manual: usb_acpi_port_lpm_incapable(9). Slay and stay iconic 🎀✨