How to stay clear of powering down particular USB tools when an equipment is put on hold
I would certainly such as to keep power supply to a USB - powered drive when the system enters into suspend (AKA S3 or "suspend - to - RAM") setting.
Generally the power is reduced while the equipment is put on hold, which creates it to be gotten down and afterwards remounted when the system is returned to. This is not actually wonderful, specifically if the drive itself sustains power management.
Although I can run it on a different power supply, I would certainly favor to need to stay clear of alloting even more circuitry for something that can, at the very least theoretically, be performed with my existing equipment.
Just how can I establish if it is feasible to do this with my system, and also just how can I schedule a certain USB tool, i.e. this unit, to constantly be treated in this manner?
I'm running ubuntu 10.10.
Discovered this ubuntuforums thread which recommends to make use of
acpitool -w to establish the readily available wake - up degree for the USB controller.
Running this on my system reveals S1 for the USB controllers:
$ acpitool -w Device S-state Status Sysfs node --------------------------------------- 1. LID S3 *enabled 2. PBTN S4 *enabled 3. PCI0 S3 *disabled no-bus:pci0000:00 4. USB0 S1 *disabled pci:0000:00:1d.0 5. USB1 S1 *disabled pci:0000:00:1d.1 6. USB2 S1 *disabled pci:0000:00:1d.2 7. USB3 S1 *disabled pci:0000:00:1d.7 8. MODM S3 *disabled 9. PCIE S4 *disabled pci:0000:00:1e.0
Which appears to be informing me that wake - up capacity can just be allowed for USB in the S1 state.
I'm not exactly sure just how valuable this is, given that giving complete power and also permitting wake - up might be orthogonal problems. It might be making it possible for wake - up just gives reduced power, so there might be a various means to enable complete power.
If activating wake - up does relate to giving complete power, it resembles I might have the ability to do what I desire by placing a USB card in the development port (I presume that is what
PCIE is?). Though I assume I would certainly need to know a little bit extra concerning this prior to trying to dig deep into a USB2 COMPUTER card.
The bit has assistance for USB 2.0 power conserving attribute
To disable it after you have actually started, you can attempt
resemble 1 >/ sys/bus/usb/ tools/ your - USB - tool / power/autosuspend
resemble "on" >/ sys/bus/usb/ tools/ your - USB - tool / power/level
For even more information search in this Link
Enabling awaken on a bus does not relate with considering that bus complete power while in suspend. It simply suggests that the system will certainly pay attention for the wakeup signal on the lines that represent that tool. Standby power is given by the ideal bus, yet this power is a lot less than the complete power for regular procedure. Including a PCI/PCIe USB card might or might not permit wake - on - USB, yet it most definitely will not give complete power to the USB ports while the equipment remains in S3. Rather, it will certainly give simply sufficient to maintain the chipset operating, concerning 200mA @ 3.3 V from what I collect from this page from Intel concerning its network adapters.
I assume this is an attribute that mosting likely to specify to a motherboard and also just controlled via the BIOS. I have a Thinkpad and also a Gigabyte motherboard that permit powering USB tools while the equipment is not awake, and also in both instances it is a setup in the BIOS as opposed to something you can transform while the system is totally started. Involve consider it, there could be a means for the Thinkpad to set up that while running, yet Thinkpads are recognized for having unique ACPI expansions for taking care of power alternatives. No matter, for both systems it is an all - or - absolutely nothing suggestion - there is no alternative for per - port or per - tool arrangement. I'm rather particular complete power USB in suspend is something that is not typical throughout PCs, and also thus, there is no mobile means to examine if it is readily available.
Although it is added equipment, I assume the most basic, most global remedy is to simply make use of a powered center.