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Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?
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my secondary PC has this specs
AMD X3 455
2x2GB DDR3 1600MHz
ATi HD3650 PCIe
it is dualboot
Windows 7 x64 SP1 (up to date)
Ubuntu 12.04 LTS x64 (up to date, kernel 3.2.0-48)
when I shutdown Windows 7 (proper shutdown, no sleep no hibernate) USB3 ports keep providing 5.0 voltage
When I reboot into Ubuntu 12.04 and do shutdown, USB3 power is killed
what I want to achieve?
to keep usb3 powered even after shutting down Ubuntu
because I am powering a 120mm fan that is cooling my router and raspberry pi and powering small portable Lenovo speakers via USB that are attached to my raspberry and are occasionally used to play some radio etc...
since it works fine after powering off windows I assume that I tweaked BIOS correctly not to power down USB3 controller (usb2 controller is powered off even after shutting down windows)
how to tweak ubuntu not to kill power to USB3 controller after shutting down?
the controller seems to be renesas NEC usb3
thank you very much in advance
when I suspend Ubuntu the power is present after that and everything works fine for me, but not after shutting it down
Power to system is part of the design of the hardware. Bios and acpi need to be set or if it can be set to do this. Some machines are sold as this as a feature. Otherwise, some settings of sleep, hibernate and non-fully power off states may do this task.
The buios setting you want is something like "VSB on usb" which translated, means "Use standby voltage for usb, and if you set 'wake up on usb' you may be led to it.
so if it was a BIOS setting that would influence it, why would Windows 7 behave differently compared to Ubuntu 12.04 with the same BIOS setup?
I even tried to install 3.8.x kernel to ubuntu to test if it was not changed but it did not provide power after shutdown
any ideas how to tweak ACPI?
output of which commands would be helpful in trying to pin this one down?
Let's be clear: There are standby, suspend, hibernate, and power off states on many PCs. Nothing works on power off. Windows is most reluctant to power off. Your options are with the other stuff. There is also a 'virtual off' where vsb stays alive, and you can power up with a quick button press. I am presuming this is what you are referring to as shut down.
There is a BIOS setting such as I have described in many (but not all) BIOSes. The 'wake up on usb' stuff requires usb to be powered by vsb. m$ is big enough to call the shots to bios writers and manufacturers - just look at UEFI. I don't know how windows does it. They were required to document windows by the EC and they wrote incomprehensible gibberish and paid millions in fines until there was some settlement, and some version of their documentation was accepted. Perhaps you can access that and see for yourself how windows did it.