Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756855Ab2JQM4B (ORCPT ); Wed, 17 Oct 2012 08:56:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35616 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755561Ab2JQMz7 (ORCPT ); Wed, 17 Oct 2012 08:55:59 -0400 Date: Wed, 17 Oct 2012 08:55:39 -0400 From: Josh Boyer To: Sarah Sharp Cc: Greg Kroah-Hartman , Michael Spang , linux-usb@vger.kernel.org, Dave Jones , Michael Spang , Linux Kernel , greno@verizon.net, Fedora Kernel Team Subject: Re: USB keyboard backlight powering down. Message-ID: <20121017125538.GA2934@hansolo.jdub.homelinux.org> References: <20121016152023.GA25506@redhat.com> <20121016165436.GA5140@kroah.com> <20121016173524.GG5378@xanatos> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121016173524.GG5378@xanatos> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2757 Lines: 60 On Tue, Oct 16, 2012 at 10:35:24AM -0700, Sarah Sharp wrote: > On Tue, Oct 16, 2012 at 09:54:36AM -0700, Greg Kroah-Hartman wrote: > > On Tue, Oct 16, 2012 at 12:45:56PM -0400, Michael Spang wrote: > > > On Tue, Oct 16, 2012 at 11:20 AM, Dave Jones wrote: > > > > Gerry (CC'd) reported a bug to us that since 3.6.1, his illuminated > > > > Logitech USB keyboard doesn't light up until he hits a key, and then > > > > it immediately powers back off, defeating the purpose of having an > > > > illumated keyboard. > > > > > > > > Looking over the 3.6.1 changelog, I see this change, which sounds > > > > like it might be responsible ? > > > > > > > > commit ee537508bdc0c00b96ac497f3d82a68f820e6182 > > > > Author: Michael Spang > > > > Date: Fri Sep 14 13:05:49 2012 -0400 > > > > > > > > Increase XHCI suspend timeout to 16ms > > > > > > I don't think this is related to your problem, as this patch is in > > > suspend/resume code. It just allows the controller more time to halt. > > > > Yeah, that looks odd. > > > > But, (adding linux-usb@vger), I think we enabled some "put the device to > > sleep if it is idle" logic for all devices, which is what is looking > > like is happening here. The keyboard is being told to go to sleep in > > order to save power. > > > > We are saving more power, but it looks like the user wants to disable > > it, which makes sense for this device. > > > > So, do we do this from within the kernel with a blacklist, or rely on > > the user knowing how to poke the proper sysfs file to turn the keyboard > > back on? > > This was the udev bug I was referring to, which I think is causing the > keyboard to have auto-suspend enabled: > > https://bugzilla.redhat.com/show_bug.cgi?id=825284 > > udev shouldn't be enabling auto-suspend of USB hids by default, since > many of them don't send a wakeup to come out of suspend when they > should. For example, most USB mice only send a wakeup even when they > are clicked, not when they are moved. That causes the user to sit > there, frustrated, as they move their mouse and wonder why their screen > doesn't unblank. Other keyboards also lose keystrokes, which means if > you pause to compose your thoughts, the first couple letters you type > gets dropped. I know we fixed that bug for F17, F18, and rawhide. I did it myself. I don't think this is udev related, but we'll double check the version. Gerry, are you using udev-182-3.fc17 or newer on your F17 install? josh -- 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/