Driver probe's currently do the following
pci_enable_device();
/* ... do some other init stuff, and eventually call ... */
request_irq();
After pci_enable_device() is called it is assumed that the device's irq
value (pci_dev->irq) has been appropriately set on success. This value
is passed into the request_irq() call.
In the case that ACPI is used to determine the irq value, it is possible
that the ACPI IRQ look up for a specific device fails and success is
returned by pci_enable_device().
The call sequence is:
pci_enable_device();
-> pci_enable_device_flags();
->do_pci_enable_device();
-> pcibios_enable_device() which, if the device
does not use MSI calls
-> pcibios_enable_irq() which maps to
acpi_pci_irq_enable()
-> acpi_pci_irq_lookup()
If acpi_pci_irq_lookup() cannot map the device's IRQ value it returns NULL
as an error. The error is returned to acpi_pci_irq_enable(), but is not
propagated further. This can result in the driver returning success for
pci_enable_device() and the driver probe attempting to call request_irq()
with dev->irq = 0.
This patch modifies acpi_pci_irq_enable() to return an error in the case
that an entry is not found in the ACPI tables.
Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: "Bjorn Helgaas" <bhelgaas@xxxxxxxxxx>
Cc: "Myron Stowe" <mstowe@xxxxxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
---
drivers/acpi/pci_irq.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 41c5e1b..9681847 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -430,6 +430,7 @@ int acpi_pci_irq_enable(struct pci_dev *dev)
} else {
dev_warn(&dev->dev, "PCI INT %c: no GSI\n",
pin_name(pin));
+ return -ENOENT;
}
return 0;
--
1.7.9.3
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