On Thu, 9 Dec 2010, Sarah Sharp wrote: > On Thu, Dec 09, 2010 at 04:46:25PM -0500, Jon 'maddog' Hall wrote: > > Sarah, > > > > If I simply "eject" (unmount) the drive instead of "safely removing it", > > then the light on the Kingston flash drive turns off and stays off, and > > when I pull the drive out and re-insert it, the drive is mounted as it > > should be. > > > > I pulled out a USB 3.0 drive that has three filesystems on it. I plug > > it in to the top USB 3.0 slot and all three partitions mount (great!) > > > > I then click on one of the icons, chose "safely remove the drive" and > > all three file systems disappear (as they should). I remove the USB > > device and plug it back in the same socket and nothing happens until I > > do an "lsusb", or until I plug it in the other USB 3.0 socket. Then all > > three filesystems are mounted again. > > I'm not sure, but I think "safely removing" a USB device actually powers > off the USB port. It's a userspace thing, not determined by the kernel. I don't know what Jon's GUI does when you click on "safely remove the drive". However the "remove" attribute in sysfs disables the port and tells the hub driver not to enable it again until a connect change has occurred. BTW, the hardware in the USB controllers used by most PCs is incapable of powering off individual ports. Perhaps xHCI offers more control. > ISTR that Alan worked on a patch for that. Alan, is > this expected behavior? No. A dmesg log with CONFIG_USB_DEBUG enabled would be most helpful. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
