Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965315Ab3IEMwA (ORCPT ); Thu, 5 Sep 2013 08:52:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41347 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965262Ab3IEMv5 (ORCPT ); Thu, 5 Sep 2013 08:51:57 -0400 Date: Thu, 5 Sep 2013 14:53:47 +0200 From: Alexander Gordeev To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, linux-pci@vger.kernel.org, linux-ide@vger.kernel.org, Tejun Heo , Ingo Molnar , Joerg Roedel , Jan Beulich , Bjorn Helgaas Subject: [PATCH v2 4/6] AHCI: Conserve interrupts with pci_enable_msi_block_part() interface Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2623 Lines: 98 Make use of the new pci_enable_msi_block_part() interface and conserve on othewise wasted interrupt resources for 10 of 16 unused MSI vectors on Intel chipsets. Signed-off-by: Alexander Gordeev --- drivers/ata/ahci.c | 46 +++++++++++++++++++++++++++------------------- 1 files changed, 27 insertions(+), 19 deletions(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index db4380d..a6bb618 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1091,26 +1091,34 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host) {} #endif -int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv) +int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports, + struct ahci_host_priv *hpriv) { int rc; unsigned int maxvec; - if (!(hpriv->flags & AHCI_HFLAG_NO_MSI)) { - rc = pci_enable_msi_block_auto(pdev, &maxvec); - if (rc > 0) { - if ((rc == maxvec) || (rc == 1)) - return rc; - /* - * Assume that advantage of multipe MSIs is negated, - * so fallback to single MSI mode to save resources - */ - pci_disable_msi(pdev); - if (!pci_enable_msi(pdev)) - return 1; - } - } + if (hpriv->flags & AHCI_HFLAG_NO_MSI) + goto intx; + + maxvec = pci_get_msi_cap(pdev); + if (maxvec < 0) + goto intx; + if (maxvec < n_ports) + goto single_msi; + + rc = pci_enable_msi_block_part(pdev, n_ports, maxvec); + if (rc < 0) + goto intx; + if (rc) + goto single_msi; + + return maxvec; +single_msi: + if (!pci_enable_msi(pdev)) + return 1; + +intx: pci_intx(pdev, 1); return 0; } @@ -1277,10 +1285,6 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) hpriv->mmio = pcim_iomap_table(pdev)[ahci_pci_bar]; - n_msis = ahci_init_interrupts(pdev, hpriv); - if (n_msis > 1) - hpriv->flags |= AHCI_HFLAG_MULTI_MSI; - /* save initial config */ ahci_pci_save_initial_config(pdev, hpriv); @@ -1327,6 +1331,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) */ n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map)); + n_msis = ahci_init_interrupts(pdev, n_ports, hpriv); + if (n_msis > 1) + hpriv->flags |= AHCI_HFLAG_MULTI_MSI; + host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports); if (!host) return -ENOMEM; -- 1.7.7.6 -- Regards, Alexander Gordeev agordeev@redhat.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/