From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiang Liu Subject: [Bugfix 1/2] x86, irq, PCI: Keep IRQ assignment for PCI devices during suspend/hibernation Date: Tue, 5 Aug 2014 11:26:17 +0800 Message-ID: <1407209178-18644-2-git-send-email-jiang.liu@linux.intel.com> References: <1407209178-18644-1-git-send-email-jiang.liu@linux.intel.com> Return-path: In-Reply-To: <1407209178-18644-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-pci-owner@vger.kernel.org To: Benjamin Herrenschmidt , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Rafael J. Wysocki" , Bjorn Helgaas , Randy Dunlap , Yinghai Lu , Borislav Petkov , Grant Likely , x86@kernel.org, Len Brown Cc: Jiang Liu , Konrad Rzeszutek Wilk , Andrew Morton , Tony Luck , Joerg Roedel , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org List-Id: linux-acpi@vger.kernel.org Now IOAPIC driver dynamically allocates IRQ numbers for IOAPIC pins. We need to keep IRQ assignment for PCI devices during suspend/hibernation, otherwise it may cause failure of suspend/hibernation due to: 1) Device driver calls pci_enable_device() to allocate an IRQ number and register interrupt handler on the returned IRQ. 2) Device driver's suspend callback calls pci_disable_device() and release assigned IRQ in turn. 3) Device driver's resume callback calls pci_enable_device() to allocate IRQ number again. A different IRQ number may be assigned by IOAPIC driver this time. 4) Now the hardware delivers interrupt to the new IRQ but interrupt handler is still registered against the old IRQ, so it breaks suspend/hibernation. To fix this issue, we keep IRQ assignment during suspend/hibernation. Flag pci_dev.dev.power.is_prepared is used to detect that pci_disable_device() is called during suspend/hibernation. Signed-off-by: Jiang Liu --- Hi Borislav, Could you please help to review the patch again since I have made changes against the previous version? Regards! Gerry --- arch/x86/pci/intel_mid_pci.c | 2 +- arch/x86/pci/irq.c | 3 ++- drivers/acpi/pci_irq.c | 4 ++++ 3 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c index 09fece368592..3865116c51fb 100644 --- a/arch/x86/pci/intel_mid_pci.c +++ b/arch/x86/pci/intel_mid_pci.c @@ -229,7 +229,7 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev) static void intel_mid_pci_irq_disable(struct pci_dev *dev) { - if (dev->irq > 0) + if (!dev->dev.power.is_prepared && dev->irq > 0) mp_unmap_irq(dev->irq); } diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c index 748cfe8ab322..bc1a2c341891 100644 --- a/arch/x86/pci/irq.c +++ b/arch/x86/pci/irq.c @@ -1256,7 +1256,8 @@ static int pirq_enable_irq(struct pci_dev *dev) static void pirq_disable_irq(struct pci_dev *dev) { - if (io_apic_assign_pci_irqs && dev->irq) { + if (io_apic_assign_pci_irqs && !dev->dev.power.is_prepared && + dev->irq) { mp_unmap_irq(dev->irq); dev->irq = 0; } diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c index 6ba463ceccc6..c96887d5289e 100644 --- a/drivers/acpi/pci_irq.c +++ b/drivers/acpi/pci_irq.c @@ -481,6 +481,10 @@ void acpi_pci_irq_disable(struct pci_dev *dev) if (!pin) return; + /* Keep IOAPIC pin configuration when suspending */ + if (dev->dev.power.is_prepared) + return; + entry = acpi_pci_irq_lookup(dev, pin); if (!entry) return; -- 1.7.10.4