From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dhcp-26-207.brq.redhat.com (unknown [89.24.186.221]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 207BC2C0094 for ; Thu, 3 Oct 2013 02:57:13 +1000 (EST) From: Alexander Gordeev To: linux-kernel@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: In-Reply-To: References: Cc: linux-mips@linux-mips.org, "VMware, Inc." , linux-nvme@lists.infradead.org, linux-ide@vger.kernel.org, linux-s390@vger.kernel.org, Andy King , linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, x86@kernel.org, Alexander Gordeev , linux-pci@vger.kernel.org, iss_storagedev@hp.com, linux-driver@qlogic.com, Tejun Heo , Bjorn Helgaas , Dan Williams , Jon Mason , Ingo Molnar , Solarflare linux maintainers , netdev@vger.kernel.org, Ralf Baechle , e1000-devel@lists.sourceforge.net, Martin Schwidefsky , linux390@de.ibm.com, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 */ -- 1.7.7.6