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authorJiang Liu <jiang.liu@linux.intel.com>2014-10-27 13:21:42 +0800
committerThomas Gleixner <tglx@linutronix.de>2014-12-16 14:08:15 +0100
commitcffe0a2b5a34c95a4dadc9ec7132690a5b0f6687 (patch)
tree136c802b57a9724e64510ae7531c7e366db479a8 /drivers/acpi
parent67dc5e701fda884d49ed5c1904986bd5333610f4 (diff)
x86, irq: Keep balance of IOAPIC pin reference count
To keep balance of IOAPIC pin reference count, we need to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. There are two cases which will cause reentrance. The first case is caused by suspend/hibernation. If pcibios_disable_irq is called during suspending/hibernating, we don't release the assigned IRQ number, otherwise it may break the suspend/hibernation. So late when pcibios_enable_irq is called during resume, we shouldn't allocate IRQ number again. The second case is that function acpi_pci_irq_enable() may be called twice for PCI devices present at boot time as below: 1) pci_acpi_init() --> acpi_pci_irq_enable() if pci_routeirq is true 2) pci_enable_device() --> pcibios_enable_device() --> acpi_pci_irq_enable() We can't kill kernel parameter pci_routeirq yet because it's still needed for debugging purpose. So flag irq_managed is introduced to track whether IRQ number is assigned by OS and to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Len Brown <lenb@kernel.org> Link: http://lkml.kernel.org/r/1414387308-27148-13-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/pci_irq.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 6e6b80eb0bba..5f1fdca65e5f 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_managed && dev->irq > 0)
+ return 0;
+
entry = acpi_pci_irq_lookup(dev, pin);
if (!entry) {
/*
@@ -456,6 +459,7 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
return rc;
}
dev->irq = rc;
+ dev->irq_managed = 1;
if (link)
snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link);
@@ -478,7 +482,7 @@ void acpi_pci_irq_disable(struct pci_dev *dev)
u8 pin;
pin = dev->pin;
- if (!pin)
+ if (!pin || !dev->irq_managed || dev->irq <= 0)
return;
/* Keep IOAPIC pin configuration when suspending */
@@ -506,6 +510,9 @@ 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) {
acpi_unregister_gsi(gsi);
+ dev->irq = 0;
+ dev->irq_managed = 0;
+ }
}