From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Stern Subject: Re: [RFC PATCH] usb/acpi: Add support usb port power off mechanism for device fixed on the motherboard Date: Fri, 11 May 2012 16:26:05 -0400 (EDT) Message-ID: References: <20120511201507.GG18754@xanatos> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from iolanthe.rowland.org ([192.131.102.54]:47627 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1760840Ab2EKU0G (ORCPT ); Fri, 11 May 2012 16:26:06 -0400 In-Reply-To: <20120511201507.GG18754@xanatos> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Sarah Sharp Cc: "Lan, Tianyu" , "lenb@kernel.org" , "gregkh@linuxfoundation.org" , "linux-acpi@vger.kernel.org" , "linux-usb@vger.kernel.org" On Fri, 11 May 2012, Sarah Sharp wrote: > On Fri, May 11, 2012 at 07:54:04PM +0000, Lan, Tianyu wrote: > > On 2012/5/12 1:44, Alan Stern wrote: > > > This doesn't matter. Disconnections will be handled by > > > usb_reset_and_verify_device(), when it is called by > > > finish_port_resume(). > > This will cause the device to be re-enumerated. Just like > > unplugged and plugged a device. I think this is not what > > we want. Disconnect and create the same device. device > > num is also change. > > Tianyu, do you have CONFIG_USB_PERSIST turned on? > > Alan, do you know if that will that only help in this case after the > host controller PCI device is in D3hot? See check_port_resume_type() in hub.c. It doesn't care what the reason is for loss connectivity during suspend or what state the host controller was in. Alan Stern