Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754610AbbFEVXC (ORCPT ); Fri, 5 Jun 2015 17:23:02 -0400 Received: from mail-ig0-f169.google.com ([209.85.213.169]:37372 "EHLO mail-ig0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752141AbbFEVW4 (ORCPT ); Fri, 5 Jun 2015 17:22:56 -0400 Date: Fri, 5 Jun 2015 16:22:52 -0500 From: Bjorn Helgaas To: Jiang Liu Cc: Thomas Gleixner , "Rafael J . Wysocki" , LKML , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, "x86 @ kernel . org" Subject: Re: [Patch v2 4/4] PCI, MSI: Optionally free legacy PCI IRQ when enabling MSI/MSI-X Message-ID: <20150605212252.GT3631@google.com> References: <1433213360-3700-1-git-send-email-jiang.liu@linux.intel.com> <1433213360-3700-5-git-send-email-jiang.liu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1433213360-3700-5-git-send-email-jiang.liu@linux.intel.com> 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: 2202 Lines: 65 >From the point of view of the generic code in this patch, freeing the IRQ isn't optional -- there's no "if" in this this patch. It's true that the default pcibios_free_irq() implementation does nothing, but the changelog of this patch should describe what this patch does. On Tue, Jun 02, 2015 at 10:49:19AM +0800, Jiang Liu wrote: > Once PCI MSI/MSI-X is enabled by the device driver, PCI device won't > make use of legacy PCI IRQ until PCI MSI/MSI-X is disabled again. > So optionally free legacy PCI IRQ when enabling MSI/MSI-X and reallocate > when disabling MSI/MSI-X. > > Signed-off-by: Jiang Liu > --- > drivers/pci/msi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index c3e7dfcf9ff5..47cf72c669f0 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -686,6 +686,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec) > msi_set_enable(dev, 1); > dev->msi_enabled = 1; > > + pcibios_free_irq(dev); > dev->irq = entry->irq; > return 0; > } > @@ -813,9 +814,10 @@ static int msix_capability_init(struct pci_dev *dev, > /* Set MSI-X enabled bits and unmask the function */ > pci_intx_for_msi(dev, 0); > dev->msix_enabled = 1; > - > msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0); > > + pcibios_free_irq(dev); > + > return 0; > > out_avail: > @@ -930,6 +932,7 @@ void pci_msi_shutdown(struct pci_dev *dev) > > /* Restore dev->irq to its default pin-assertion irq */ > dev->irq = desc->msi_attrib.default_irq; > + pcibios_alloc_irq(dev); > } > > void pci_disable_msi(struct pci_dev *dev) > @@ -1030,6 +1033,7 @@ void pci_msix_shutdown(struct pci_dev *dev) > msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); > pci_intx_for_msi(dev, 1); > dev->msix_enabled = 0; > + pcibios_alloc_irq(dev); > } > > void pci_disable_msix(struct pci_dev *dev) > -- > 1.7.10.4 > -- 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/