diff options
| author | Jiang Liu <jiang.liu@linux.intel.com> | 2014-10-27 13:21:42 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2014-12-16 14:08:15 +0100 |
| commit | cffe0a2b5a34c95a4dadc9ec7132690a5b0f6687 (patch) | |
| tree | 136c802b57a9724e64510ae7531c7e366db479a8 /drivers/acpi | |
| parent | 67dc5e701fda884d49ed5c1904986bd5333610f4 (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.c | 11 |
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; + } } |