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| 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 /arch/x86/pci/intel_mid_pci.c | |
| parent | 67dc5e701fda884d49ed5c1904986bd5333610f4 (diff) | |
| download | linux-cffe0a2b5a34c95a4dadc9ec7132690a5b0f6687.tar.bz2 | |
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 'arch/x86/pci/intel_mid_pci.c')
| -rw-r--r-- | arch/x86/pci/intel_mid_pci.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c index b9958c364075..44b9271580b5 100644 --- a/arch/x86/pci/intel_mid_pci.c +++ b/arch/x86/pci/intel_mid_pci.c @@ -210,6 +210,9 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev) { int polarity; + if (dev->irq_managed && dev->irq > 0) + return 0; + if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER) polarity = 0; /* active high */ else @@ -224,13 +227,18 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev) if (mp_map_gsi_to_irq(dev->irq, IOAPIC_MAP_ALLOC) < 0) return -EBUSY; + dev->irq_managed = 1; + return 0; } static void intel_mid_pci_irq_disable(struct pci_dev *dev) { - if (!mp_should_keep_irq(&dev->dev) && dev->irq > 0) + if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed && + dev->irq > 0) { mp_unmap_irq(dev->irq); + dev->irq_managed = 0; + } } struct pci_ops intel_mid_pci_ops = { |