Re: [ACPI] Re: [Pcihpd-discuss] RE: [patch 2/2] acpi: add ability to derive irq when doing a surpriseremoval of an adapter

Kristen Accardi
2005-10-21T21:28:34Z

This patch will allow the acpi code to correctly disable the irq when an
adapter has been "surprise" removed. The INTERRUPT_PIN value is stored
in the pci_dev structure at probe time, and if the acpi code attempts to
read the INTERRUPT_PIN from config space and detects that the adapter is
not present, it will use the stored value instead.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>

---
I've re-worked this patch as you suggested. the INTERRUPT_PIN was read
in many different places in the code, so I hope that this is the right
place to save off the value. Thanks for taking a look.

drivers/acpi/pci_irq.c | 10 ++++++++++
drivers/pci/probe.c | 1 +
include/linux/pci.h | 1 +
3 files changed, 12 insertions(+)

Index: linux-2.6.13/drivers/acpi/pci_irq.c
===================================================================
--- linux-2.6.13.orig/drivers/acpi/pci_irq.c
+++ linux-2.6.13/drivers/acpi/pci_irq.c
@@ -504,6 +504,16 @@ void acpi_pci_irq_disable(struct pci_dev
return_VOID;

pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
+
+ /*
+ * If a device has been "surprise" removed via
+ * hotplug, the pin value will be invalid
+ * In this case, we should use the stored
+ * pin value from the pci_dev structure
+ */
+ if (pin == 0xff)
+ pin = dev->pin;
+
if (!pin)
return_VOID;
pin--;
Index: linux-2.6.13/drivers/pci/probe.c
===================================================================
--- linux-2.6.13.orig/drivers/pci/probe.c
+++ linux-2.6.13/drivers/pci/probe.c
@@ -571,6 +571,7 @@ static void pci_read_irq(struct pci_dev
unsigned char irq;

pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq);
+ dev->pin = irq;
if (irq)
pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
dev->irq = irq;
Index: linux-2.6.13/include/linux/pci.h
===================================================================
--- linux-2.6.13.orig/include/linux/pci.h
+++ linux-2.6.13/include/linux/pci.h
@@ -98,6 +98,7 @@ struct pci_dev {
unsigned int class; /* 3 bytes: (base,sub,prog-if) */
u8 hdr_type; /* PCI header type (`multi' flag masked out) */
u8 rom_base_reg; /* which config register controls the ROM */
+ u8 pin; /* which interrupt pin this device uses */

struct pci_driver *driver; /* which driver has allocated this device */
u64 dma_mask; /* Mask of the bits of bus address this