From patchwork Thu Jan 10 09:24:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aaron Lu X-Patchwork-Id: 1959021 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 62CB43FF0F for ; Thu, 10 Jan 2013 09:28:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753140Ab3AJJ2E (ORCPT ); Thu, 10 Jan 2013 04:28:04 -0500 Received: from mga09.intel.com ([134.134.136.24]:4760 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752303Ab3AJJY3 (ORCPT ); Thu, 10 Jan 2013 04:24:29 -0500 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP; 10 Jan 2013 01:23:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,443,1355126400"; d="scan'208";a="244528118" Received: from aaronlu.sh.intel.com ([10.239.36.111]) by orsmga001.jf.intel.com with ESMTP; 10 Jan 2013 01:24:26 -0800 From: Aaron Lu To: Jeff Garzik , James Bottomley , "Rafael J. Wysocki" , Alan Stern , Tejun Heo Cc: Aaron Lu , Jeff Wu , linux-ide@vger.kernel.org, linux-pm@vger.kernel.org, linux-scsi@vger.kernel.org, linux-acpi@vger.kernel.org, Aaron Lu Subject: [PATCH v12 8/9] libata: do not suspend port if normal ODD is attached Date: Thu, 10 Jan 2013 17:24:29 +0800 Message-Id: <1357809870-18816-9-git-send-email-aaron.lu@intel.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1357809870-18816-1-git-send-email-aaron.lu@intel.com> References: <1357809870-18816-1-git-send-email-aaron.lu@intel.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org For ODDs, the upper layer will poll for media change every few seconds, which will make it enter and leave suspend state very often. And as each suspend will also cause a hard/soft reset, the gain of runtime suspend is very little while the ODD may malfunction after constantly being reset. So the idle callback here will not proceed to suspend if a non-ZPODD capable ODD is attached to the port. Signed-off-by: Aaron Lu Acked-by: Tejun Heo --- drivers/ata/libata-core.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 65a362e..5f9de1c 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5408,8 +5408,27 @@ static int ata_port_resume(struct device *dev) return rc; } +/* + * For ODDs, the upper layer will poll for media change every few seconds, + * which will make it enter and leave suspend state every few seconds. And + * as each suspend will cause a hard/soft reset, the gain of runtime suspend + * is very little and the ODD may malfunction after constantly being reset. + * So the idle callback here will not proceed to suspend if a non-ZPODD capable + * ODD is attached to the port. + */ static int ata_port_runtime_idle(struct device *dev) { + struct ata_port *ap = to_ata_port(dev); + struct ata_link *link; + struct ata_device *adev; + + ata_for_each_link(link, ap, HOST_FIRST) { + ata_for_each_dev(adev, link, ENABLED) + if (adev->class == ATA_DEV_ATAPI && + !zpodd_dev_enabled(adev)) + return -EBUSY; + } + return pm_runtime_suspend(dev); }