From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sarah Sharp Subject: Re: [RFC PATCH] usb/acpi: Add support usb port power off mechanism for device fixed on the motherboard Date: Tue, 15 May 2012 13:00:47 -0700 Message-ID: <20120515200047.GA20507@xanatos> References: <20120511202113.GH18754@xanatos> <20120511235922.GJ18754@xanatos> <20120512001722.GA28011@kroah.com> <20120514232123.GK18754@xanatos> <4FB268CA.9060304@intel.com> <20120515151800.GC23916@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mga09.intel.com ([134.134.136.24]:11111 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966685Ab2EOUBB (ORCPT ); Tue, 15 May 2012 16:01:01 -0400 Content-Disposition: inline In-Reply-To: <20120515151800.GC23916@kroah.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Greg KH Cc: Lan Tianyu , Alan Stern , Dan Williams , lenb@kernel.org, linux-acpi@vger.kernel.org, linux-usb@vger.kernel.org On Tue, May 15, 2012 at 08:18:00AM -0700, Greg KH wrote: > On Tue, May 15, 2012 at 10:31:38PM +0800, Lan Tianyu wrote: > > Since alan suggested we should start simpler version(power > > down port that have no devices attached) firstly. And we > > also should provide general power off mechanism. > > > > I have a proposal. > > first: add portx_power_control sys file. > > echo "auto" => portx_power_control > > check whether there is a device. if no, send the clear > > USB_PORT_FEAT_POWER request. (since general way > > to control port power is via set or clear PORT_POWER) > > > > echo "on" => portx_power_control > > send the set USB_PORT_FEAT_POWER request. > > No "off"? Yeah, we probably need an "off" for those libusb and ModemManager developers who want to try and simulate a disconnect of a misbehaving device. Sarah Sharp