From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Jiang Liu To: Benjamin Herrenschmidt , Thomas Gleixner , Grant Likely , Ingo Molnar , "H. Peter Anvin" , "Rafael J. Wysocki" , Bjorn Helgaas , Randy Dunlap , Yinghai Lu , Len Brown Cc: Jiang Liu , Konrad Rzeszutek Wilk , Andrew Morton , Tony Luck , Joerg Roedel , Paul Gortmaker , Greg Kroah-Hartman , x86@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [RFC Patch V2 07/16] x86, irq, ACPI: protect acpi_pci_irq_enable() from reentrance Date: Tue, 17 Jun 2014 13:29:46 +0800 Message-Id: <1402982995-13747-8-git-send-email-jiang.liu@linux.intel.com> In-Reply-To: <1402982995-13747-1-git-send-email-jiang.liu@linux.intel.com> References: <1402982995-13747-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Function acpi_pci_irq_enable() may be called twice for each PCI device present at boot time as below: 1) pci_acpi_init() --> acpi_pci_irq_enable() 2) pci_enable_device() --> pcibios_enable_device() --> acpi_pci_irq_enable() So protect acpi_pci_irq_enable() from reentrance to correctly manage IOAPIC pin reference count. Signed-off-by: Jiang Liu --- drivers/acpi/pci_irq.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c index 6ba463ceccc6..9d2ebd5fd9aa 100644 --- a/drivers/acpi/pci_irq.c +++ b/drivers/acpi/pci_irq.c @@ -413,6 +413,9 @@ int acpi_pci_irq_enable(struct pci_dev *dev) return 0; } + if (dev->irq > 0) + return 0; + entry = acpi_pci_irq_lookup(dev, pin); if (!entry) { /* @@ -498,6 +501,8 @@ void acpi_pci_irq_disable(struct pci_dev *dev) */ dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin)); - if (gsi >= 0 && dev->irq > 0) + if (gsi >= 0 && dev->irq > 0) { acpi_unregister_gsi(gsi); + dev->irq = 0; + } } -- 1.7.10.4