Appreciate any USB power expert can help me on those Linux USB power management puzzles: Q1: I found some USB material mentioned : Relationship between ACPI Dx(e.g. D0/D1/D3) states and USB PM states (active/suspended) is orthogonal. Suspend/resume might not effect device Dx state. Is it a correct statement for general usb device? Q2: How to tell USB device’s ACPI Dx state. It seems lsusb can’t tell us those info. (lspci works for PCI device’s Dx state) Q3: How to tell USB device’s suspension state? will any query via urb will cause resume of USB device? Q4: should USB device driver response to do some device-specific power action (e.g. device register writing) to put a specific USB device into low power state when responding to suspend action? Q5: If Q4 is Yes, should device vendor respond for those device-specific code? will Linux kernel code typically incorporate those device-specific code? Thanks! Samuel -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
