Comment 26 for bug 1461986

Yes, I am able to change it, and reactivate it by booting into Windows. Here is a detailed summary of what I did:

I shut down my Ubuntu, inserted the HDD containing Windows 8 to my optical bay, and booted into Windows.

I found that USB charging was already on in the VAIO program. I shut down windows and checked if it was actuallly on, but the USB was not powered.

I booted again into Windows and switched it off. I could successfully switched it off and shut down my PC. When I checked if USB is powered, it obviously was not powered.

I booted into windows yet again and switched it on. Now when I shut it down, I found that I could charge my mobile successfully. In short, with windows I was able to successfully reactivate USB Charging.

Now I switched the feature off from Windows and booted into Ubuntu, and found it exactly as before, ie Even-though the feature was off, usb_charging had a value of 1, and I could not change it to 0.

To test further, I booted into Windows, switched the feature back on, tested it, and booted into linux. I got the same response. usb_charging had a value of 1, and I could not change it to 0.

I should add that windows boots with UEFI from the HDD in the optical bay, while Ubuntu boots in Lagacy mode from the internal SSD. To see if changing from UEFI to Lagacy had any effect, I booted into Windows, switched it on and shut down. Now I confirmed that my phone is being charged. I switched to Legacy, and yet again, I can charge my phone when the PC is shut down.

If you want, I can test from UEFI booted Ubuntu.