Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753508Ab1BSKQT (ORCPT ); Sat, 19 Feb 2011 05:16:19 -0500 Received: from mail-px0-f174.google.com ([209.85.212.174]:63542 "EHLO mail-px0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751665Ab1BSKQS (ORCPT ); Sat, 19 Feb 2011 05:16:18 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=FM1L6JF+fj6CdpkS+TanzWEA9AMNZ32KgWWNMzV6kv/cVidQGOgFxjTprgdVcjsxj7 NpQU1huut+WfHBsybPRUwHjjyt+sm6uIsZ5bvfr+Y0hVxwCUuwUw8dcpUIlfB4gK85TO m9kUjNdqkIjNrMfZAN6S57zaodQzDNCJSDAjc= MIME-Version: 1.0 In-Reply-To: <20110219100017.GA29493@n2100.arm.linux.org.uk> References: <201102181928.05911.rjw@sisk.pl> <201102182120.29977.rjw@sisk.pl> <20110218202744.GA19427@n2100.arm.linux.org.uk> <20110219100017.GA29493@n2100.arm.linux.org.uk> Date: Sat, 19 Feb 2011 11:16:17 +0100 X-Google-Sender-Auth: KfExX5es7dQGtFw4ad48XA9_ND0 Message-ID: Subject: Re: platform/i2c busses: pm runtime and system sleep From: Linus Walleij To: Russell King - ARM Linux Cc: "Rafael J. Wysocki" , Rabin Vincent , khilman@ti.com, magnus.damm@gmail.com, LKML , stern@rowland.harvard.edu, linux-i2c@vger.kernel.org, linux-pm@lists.linux-foundation.org, linux-arm-kernel Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1384 Lines: 33 2011/2/19 Russell King - ARM Linux : > [Me] >> Both of these problems are solved by elegance if we use runtime >> PM, since it will provide a hysteresis timeout that can be triggered >> from interrupt context and call the idling hooks in process context. > > So what's the interdependence with the platform bus that was being talked > about earlier in this thread? That's about consistency of runtime PM semantics across different buses as I understand it. We have both platform bus and AMBA bus devices in the system, so it is desireable if the semantics of their runtime PM are identical. If I understand it, the difference is that the platform bus will call runtime_suspend() on the device even if it was already in suspended state, so the question is about whether the AMBA runtime PM should do this too since it is similar to the platform bus, or if it should go for the more intutive approach of not suspending suspended hardware. I think the current patch from Rabin as it stands does the latter, and is good as it stands. It's the other buses and their drivers that need patching. Yours, Linus Walleij -- 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/