Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756938AbZAARpt (ORCPT ); Thu, 1 Jan 2009 12:45:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756179AbZAARpj (ORCPT ); Thu, 1 Jan 2009 12:45:39 -0500 Received: from netrider.rowland.org ([192.131.102.5]:2273 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756176AbZAARpi (ORCPT ); Thu, 1 Jan 2009 12:45:38 -0500 Date: Thu, 1 Jan 2009 12:45:36 -0500 (EST) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: "Alexander E. Patrakov" cc: USB list , Kernel development list Subject: Re: Enable CONFIG_USB_SUSPEND by default or some mobile HD can't be unplugged safely In-Reply-To: <495CFE38.6070603@gmail.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1650 Lines: 42 On Thu, 1 Jan 2009, Alexander E. Patrakov wrote: > Yan Li wrote: > > Hello List, > > > > By default CONFIG_USB_SUSPEND is not enabled and today I got bite by > > this when I got a new WDC My Book hard drive. I have no way to unplug > > it safely, according to it's manual, with a kernel that doesn't have > > CONFIG_USB_SUSPEND=y. > > > > On it's manual read "you should unplug and remove the device only when > > the light is off." On Linux unmounting it won't turn it's light off > > and I can feel it's motor is still running. The only way to unplug it > > properly on a Linux system, as to my knowledge, is to echo `suspend' > > to `/sys/bus/usb/devices/$DEV/power/level'. And one has to have > > CONFIG_USB_SUSPEND=y to do this. > > > > On Windows and Mac OS, `safely remove this device' function effectly > > turns it into `suspend' mode, and it's light off. > > You have obviously tested only Windows XP, because Vista doesn't cut the > power for at least some USB devices. Yan never said that Windows cuts any power; he only said that the light turns off. This is accomplished by disabling the USB port, not by cutting power. > And congratulations for obtaining a > Vista-incompatible hard drive (of course, joking). > > BTW, does the "eject /dev/$DEV" command help? I wouldn't expect it to help, since it doesn't disable the port or put the device into suspend mode. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/