Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754130AbaJASpG (ORCPT ); Wed, 1 Oct 2014 14:45:06 -0400 Received: from mail-wi0-f174.google.com ([209.85.212.174]:52464 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753899AbaJASpB (ORCPT ); Wed, 1 Oct 2014 14:45:01 -0400 MIME-Version: 1.0 In-Reply-To: <20141001184304.GA6832@svl-evodev-groeck.juniper.net> References: <20141001184304.GA6832@svl-evodev-groeck.juniper.net> Date: Wed, 1 Oct 2014 11:44:59 -0700 Message-ID: Subject: Re: Fwd: [Proposal] PM sleep children of inactive I2C bus segments off Masters in multi-master systems From: Danielle Costantino To: Guenter Roeck Cc: linux-i2c , Bjorn Helgaas , Jiri Kosina , Andrew Morton , "David S. Miller" , Greg Kroah-Hartman , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-doc@vger.kernel.org" , Rajat Jain Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Re-sending Proposal: Currently I2C mux devices that support multiple master arbitration are the i2c-mux-pca9541 and i2c-arb-gpio-challenge drivers. I propose to add the ability to configure an interrupt pin from the Master Selector device to indicate that bus ownership has been lost. Once the device loses ownership, all of its children should enter a pm sleep mode (as you can't talk to them at this point) until master-ship has been reacquired. This has come up as an issue when the master loses control over a bus the return code of all transactions to its lave devices is EIO (not very helpful). Any comments would be appreciated, I am just looking if there is interest in this. Thanks, On Wed, Oct 1, 2014 at 11:43 AM, Guenter Roeck wrote: > On Wed, Oct 01, 2014 at 11:39:49AM -0700, Danielle Costantino wrote: >> added proper mailing lists...I hope >> > > Hi Danielle, > > I don't see the actual proposal, and I don't find anything on the web > either when looking for the headline :-(. > > Guenter -- - Danielle Costantino -- 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/