Re: Enable CONFIG_USB_SUSPEND by default or some mobile HD can't be unplugged safely

Yan Li
2009-01-03T02:33:25Z

On Fri, Jan 02, 2009 at 11:04:40AM -0500, Alan Stern wrote:
> > Now I know 3 methods supposed can be used to shut the device:
> > 1. (Alan Stern said Windows use this) cut the USB port's power
>
> I said no such thing! In fact, I said exactly the opposite: Windows
> does _not_ cut the port's power. Instead it disables the port.

Sorry, my mistake.

> The best approach is to send a SYNCHRONIZE CACHE command followed by
> START-STOP (if the device supports it), and then to disable or suspend
> the port. In Linux, those two commands will be sent automatically if
> you unbind the device from usb-storage. The suspend has to be done
> manually unless you have set up a udev rule (or something equivalent)
> to enable autosuspend for the device. Of course, this requires
> CONFIG_USB_SUSPEND.

Quite clear, thanks.

--
Li, Yan