Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765713AbXIMU3R (ORCPT ); Thu, 13 Sep 2007 16:29:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755451AbXIMU3F (ORCPT ); Thu, 13 Sep 2007 16:29:05 -0400 Received: from mail.gmx.net ([213.165.64.20]:43700 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753997AbXIMU3E (ORCPT ); Thu, 13 Sep 2007 16:29:04 -0400 X-Authenticated: #20450766 X-Provags-ID: V01U2FsdGVkX186RNkURdU6SPAx2n5Xgrxx2dZfVmqB86osuVTRaf +fEZJZD81ahUx3 Date: Thu, 13 Sep 2007 22:29:03 +0200 (CEST) From: Guennadi Liakhovetski To: Michael Mauch cc: linux-kernel@vger.kernel.org Subject: Re: wake up from a serial port In-Reply-To: <20070912210639.GA10172@elmicha> Message-ID: References: <200709100831.l8A8VUH6015446@imap1.linux-foundation.org> <20070910132703.2dd92485@the-village.bc.nu> <20070911081220.GA20847@flint.arm.linux.org.uk> <20070911121057.34b9e066@the-village.bc.nu> <20070912210639.GA10172@elmicha> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1495 Lines: 38 On Wed, 12 Sep 2007, Michael Mauch wrote: > Guennadi Liakhovetski wrote: > > > Enable wakeup from serial ports, make it run-time configurable over sysfs, > > e.g., > > > > echo enabled > /sys/devices/platform/serial8250.0/tty/ttyS0/power/wakeup > > Interesting, but how does that work from a user's/hardware perspective? > > Do I have to pull DSR/RI to +12V? Can I use one of the other pins to get > these +12V (i.e. a switch and a resistor to shorten these pins is > enough)? > > And probably in the BIOS I have to enable "wake on modem ring" (or > something similar)? It depends on the hardware. In principle, with this patch _if_ your system can suspend while keeping the UART powered on and the interrupt from this UART can wake up your system, then using this patch and the command above you'll be able to also keep the UART configured, i.e., prevent the driver from suspending it during suspend and then an interrupt from this UART will wake up the system. How you generate this interrupt - doesn't matter. Whether it is a received byte, or a modem line toggle, as long as it produces an interrupt, the system will wake up. Don't know whether "normal" PCs can do that and if yes - how. Thanks Guennadi --- Guennadi Liakhovetski - 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/