From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] libata: Add ALPM power state accounting to the AHCI driver Date: Mon, 16 Nov 2009 03:06:32 +0900 Message-ID: <4B004328.8060807@kernel.org> References: <20091113192429.4dfc9c39@infradead.org> <4AFFB65F.3020201@kernel.org> <4AFFBB75.7050601@pobox.com> <20091115094630.1785b5ca@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:51531 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753346AbZKOSHo (ORCPT ); Sun, 15 Nov 2009 13:07:44 -0500 In-Reply-To: <20091115094630.1785b5ca@infradead.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Arjan van de Ven Cc: Jeff Garzik , linux-ide@vger.kernel.org, akpm@linux-foundation.org Arjan van de Ven wrote: > On Sun, 15 Nov 2009 03:27:33 -0500 > Jeff Garzik wrote: > >> What little there is of driver-specific behavior can be handled from >> existing callbacks (->enable_pm) or by creating a driver-specific >> function that calls a generic function (eg. ahci_alpm_set_accounting >> could call ata_alpm_set_accounting, before twiddling AHCI's >> PORT_IRQ_MASK). > > the whole concept of needing that accounting flag is AHCI specific; > if ever any of the other chip drivers goes to do ALPM, it'll be using > explicit software control, which doesn't need this kind of enable flag; > The only reason there is an enable flag is that the hw based accounting > is resulting in extra interrupts that you don't want except when you > want the accounting (read: powertop is running) There's DIPM. -- tejun