From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [rft]power management for usbtouch Date: Mon, 30 Jun 2008 12:30:24 -0400 Message-ID: <20080630122901.ZZRA012@mailhub.coreip.homeip.net> References: <20080630115953.ZZRA012@mailhub.coreip.homeip.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from yx-out-2324.google.com ([74.125.44.30]:41787 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751650AbYF3Qa2 (ORCPT ); Mon, 30 Jun 2008 12:30:28 -0400 Received: by yx-out-2324.google.com with SMTP id 31so288668yxl.1 for ; Mon, 30 Jun 2008 09:30:27 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Alan Stern Cc: Oliver Neukum , Ville Syrj?l? , daniel.ritz@gmx.ch, Jiri Kosina , linux-usb@vger.kernel.org, linux-input@vger.kernel.org On Mon, Jun 30, 2008 at 12:16:13PM -0400, Alan Stern wrote: > On Mon, 30 Jun 2008, Dmitry Torokhov wrote: > > > > My feeling is that we will leave manual suspension in the kernel. The > > > code passed to the USB driver's suspend method will be changed so that > > > the method can tell whether it is being called for a system sleep vs. > > > an autosuspend vs. a manual suspend. > > > > > > > Ok, I see... So what does a device do when it is suspended and a > > request comes in? Does it automatically resume and service the request > > (and potentially goes back to sleep)? Does it queue the request for > > later? Ignore it? Is it a system-wide policy or up to the device > > [class]? > > What sort of request do you mean? If a device is suspended, it _can't_ > receive any data (requests or otherwise) over the USB bus. > > If a device receives data over some other channel (like a mouse getting > a button click) while it is suspended, its behavior depends on the > settings at the time it was suspended. If remote wakeup was disabled > then the device does essentially nothing (maybe it remembers the data > for later, maybe not). If remote wakeup was enabled then the device > should send a wakeup request to the host. > I was talking about system-initiated requests... Setting LED on a keyboard, setting rate on a mouse, uploading a force-feedback effect, writing a sector on a disk, etc... -- Dmitry