From patchwork Wed Oct 2 10:48:26 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Gordeev X-Patchwork-Id: 2976341 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 700399F288 for ; Wed, 2 Oct 2013 16:57:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5845F20464 for ; Wed, 2 Oct 2013 16:57:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CE852045E for ; Wed, 2 Oct 2013 16:57:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753839Ab3JBQ5Z (ORCPT ); Wed, 2 Oct 2013 12:57:25 -0400 Received: from 221-186-24-89.in-addr.arpa ([89.24.186.221]:25195 "EHLO dhcp-26-207.brq.redhat.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753676Ab3JBQ5X (ORCPT ); Wed, 2 Oct 2013 12:57:23 -0400 Received: from dhcp-26-207.brq.redhat.com (localhost [127.0.0.1]) by dhcp-26-207.brq.redhat.com (8.14.5/8.14.5) with ESMTP id r92Aqr8H002416; Wed, 2 Oct 2013 12:52:54 +0200 Received: (from agordeev@localhost) by dhcp-26-207.brq.redhat.com (8.14.5/8.14.5/Submit) id r92Aqpe1002412; Wed, 2 Oct 2013 12:52:51 +0200 From: Alexander Gordeev To: linux-kernel@vger.kernel.org Cc: Alexander Gordeev , Bjorn Helgaas , Ralf Baechle , Michael Ellerman , Benjamin Herrenschmidt , Martin Schwidefsky , Ingo Molnar , Tejun Heo , Dan Williams , Andy King , Jon Mason , Matt Porter , linux-pci@vger.kernel.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux390@de.ibm.com, linux-s390@vger.kernel.org, x86@kernel.org, linux-ide@vger.kernel.org, iss_storagedev@hp.com, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, e1000-devel@lists.sourceforge.net, linux-driver@qlogic.com, Solarflare linux maintainers , "VMware, Inc." , linux-scsi@vger.kernel.org Subject: [PATCH RFC 10/77] ahci: Check MRSM bit when multiple MSIs enabled Date: Wed, 2 Oct 2013 12:48:26 +0200 Message-Id: X-Mailer: git-send-email 1.7.7.6 In-Reply-To: References: Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Do not trust the hardware and always check if MSI Revert to Single Message mode was enforced. Fall back to the single MSI mode in case it did. Not doing so might screw up the interrupt handling. Signed-off-by: Alexander Gordeev --- drivers/ata/ahci.c | 17 +++++++++++++++++ drivers/ata/ahci.h | 1 + 2 files changed, 18 insertions(+), 0 deletions(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index f1c8838..3a39cc8 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1091,6 +1091,14 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host) {} #endif +static int ahci_get_mrsm(struct ahci_host_priv *hpriv) +{ + void __iomem *mmio = hpriv->mmio; + u32 ctl = readl(mmio + HOST_CTL); + + return ctl & HOST_MRSM; +} + int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports, struct ahci_host_priv *hpriv) { @@ -1116,6 +1124,15 @@ int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports, if (rc) goto intx; + /* + * Fallback to single MSI mode if the controller enforced MRSM mode + */ + if (ahci_get_mrsm(hpriv)) { + pci_disable_msi(pdev); + printk(KERN_INFO "ahci: MRSM is on, fallback to single MSI\n"); + goto single_msi; + } + return nvec; single_msi: diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h index 1145637..19bc846 100644 --- a/drivers/ata/ahci.h +++ b/drivers/ata/ahci.h @@ -91,6 +91,7 @@ enum { /* HOST_CTL bits */ HOST_RESET = (1 << 0), /* reset controller; self-clear */ HOST_IRQ_EN = (1 << 1), /* global IRQ enable */ + HOST_MRSM = (1 << 2), /* MSI Revert to Single Message */ HOST_AHCI_EN = (1 << 31), /* AHCI enabled */ /* HOST_CAP bits */