It is also about the power draw on the processor power and the system power from having a USB controller working. Having any USB plugged adds noticeable amount of power.
I am hoping that telling the kernel, as per the suggestions here, to unpower it that the controller goes back to "sleep mode". Also it would be convenient if can I bring the device backup with out unplugging it. When I have a moment at work, I will get some empirical data if this works or not. On Tue, Jan 23, 2024, 5:51 AM Tomas Kuchta <[email protected]> wrote: > On Tue, Jan 23, 2024, 01:00 Ted Mittelstaedt <[email protected]> > wrote: > > > I've messed with this before trying to troubleshoot USB cams. > > > > It's highly dependent on the USB hardware. Not all USB devices implement > > "low power" mode. > > > > Your best shot is to get a good USB 4 port hub - not a crappy one - a > good > > one and the good ones > > Implement power control and can cut power to a USB device if you command > > them to. > > . > > > This is not about how the USB devices (mis)behave. They would not be trying > to control the devices, but the USB host(s) in the PC/laptop, I presume. > > USB host can, and will cut power to the bus when directed. > > While I am as guilty as any man - the world really sucks when people who > think they understand stuff speak with undoubted authority about stuff. > > Hole it helps, -T > > > >
