From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761358AbYG3Xih (ORCPT ); Wed, 30 Jul 2008 19:38:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761286AbYG3XiJ (ORCPT ); Wed, 30 Jul 2008 19:38:09 -0400 Received: from ns1.suse.de ([195.135.220.2]:35874 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760896AbYG3XiH (ORCPT ); Wed, 30 Jul 2008 19:38:07 -0400 Date: Wed, 30 Jul 2008 16:27:17 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jeff Garzik , Tejun Heo , Peer Chen , Volker Armin Hemmann Subject: [patch 16/29] ahci: retry enabling AHCI a few times before spitting out WARN_ON() Message-ID: <20080730232717.GQ30670@suse.de> References: <20080730231003.655833364@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="ahci-retry-enabling-ahci-a-few-times-before-spitting-out-warn_on.patch" In-Reply-To: <20080730232451.GA30670@suse.de> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.25-stable review patch. If anyone has any objections, please let us know. ------------------ From: Tejun Heo commit 15fe982e429e0e6b7466719acb6cfd9dbfe47f0c upstream ahci: retry enabling AHCI a few times before spitting out WARN_ON() Some chips need AHCI_EN set more than once to actually set it. Try a few times before giving up and spitting out WARN_ON(). Signed-off-by: Tejun Heo Cc: Peer Chen Cc: Volker Armin Hemmann Signed-off-by: Jeff Garzik Cc: Chuck Ebbert Signed-off-by: Greg Kroah-Hartman --- drivers/ata/ahci.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -634,16 +634,27 @@ static inline void __iomem *ahci_port_ba static void ahci_enable_ahci(void __iomem *mmio) { + int i; u32 tmp; /* turn on AHCI_EN */ tmp = readl(mmio + HOST_CTL); - if (!(tmp & HOST_AHCI_EN)) { + if (tmp & HOST_AHCI_EN) + return; + + /* Some controllers need AHCI_EN to be written multiple times. + * Try a few times before giving up. + */ + for (i = 0; i < 5; i++) { tmp |= HOST_AHCI_EN; writel(tmp, mmio + HOST_CTL); tmp = readl(mmio + HOST_CTL); /* flush && sanity check */ - WARN_ON(!(tmp & HOST_AHCI_EN)); + if (tmp & HOST_AHCI_EN) + return; + msleep(10); } + + WARN_ON(1); } /** --