From patchwork Wed Nov 21 11:50:39 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aaron Lu X-Patchwork-Id: 200661 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E38B22C008E for ; Wed, 21 Nov 2012 22:50:51 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754553Ab2KULut (ORCPT ); Wed, 21 Nov 2012 06:50:49 -0500 Received: from mga03.intel.com ([143.182.124.21]:33823 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754541Ab2KULus (ORCPT ); Wed, 21 Nov 2012 06:50:48 -0500 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga101.ch.intel.com with ESMTP; 21 Nov 2012 03:50:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.83,293,1352102400"; d="scan'208";a="170959166" Received: from aaronlu.sh.intel.com ([10.239.36.69]) by AZSMGA002.ch.intel.com with ESMTP; 21 Nov 2012 03:50:45 -0800 From: Aaron Lu To: Jeff Garzik , Tejun Heo , "Rafael J. Wysocki" , Alan Stern Cc: James Bottomley , Jeff Wu , Aaron Lu , linux-ide@vger.kernel.org, linux-linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH v10 10/10] libata: do not suspend port if normal ODD is attached Date: Wed, 21 Nov 2012 19:50:39 +0800 Message-Id: <1353498639-27631-11-git-send-email-aaron.lu@intel.com> X-Mailer: git-send-email 1.7.12.4 In-Reply-To: <1353498639-27631-1-git-send-email-aaron.lu@intel.com> References: <1353498639-27631-1-git-send-email-aaron.lu@intel.com> Sender: linux-ide-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org For ODDs, the upper layer will poll for media change every a few seconds, which will make it enter and leave suspend state very oftern. And as each suspend will also cause a hard/soft reset, the gain of runtime suspend is very little while the ODD may mis-function 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 --- 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 97987e7..9cdfb04 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -5406,8 +5406,27 @@ static int ata_port_resume(struct device *dev) return rc; } +/* + * For ODDs, the upper layer will poll for media change every a few seconds, + * which will make it enter and leave suspend state every a few seconds. And + * as each suspend will cause a hard/soft reset, the gain of runtime suspend + * is very little and the ODD may mis-function 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); }