i386/x86_84: disable PCI resource decode on device disable

From: Rajesh Shah
Date: Wed May 03 2006 - 18:31:41 EST



When a PCI device is disabled via pci_disable_device(), it's still
left decoding its BAR resource ranges even though its driver
will have likely released those regions (and may even have
unloaded). pci_enable_device() already explicitly enables
BAR resource decode for the device being enabled. This patch
disables resource decode for the PCI device being disabled,
making it symmetric with the enable call.

I saw this while doing something else, not because of a
problem report. Still, seems to be the correct thing to do.

Signed-off-by: Rajesh Shah <rajesh.shah@xxxxxxxxx>

arch/i386/pci/common.c | 1 +
arch/i386/pci/i386.c | 9 +++++++++
arch/i386/pci/pci.h | 1 +
3 files changed, 11 insertions(+)

Index: linux-2.6.17-rc3-git7/arch/i386/pci/common.c
===================================================================
--- linux-2.6.17-rc3-git7.orig/arch/i386/pci/common.c
+++ linux-2.6.17-rc3-git7/arch/i386/pci/common.c
@@ -288,6 +288,7 @@ int pcibios_enable_device(struct pci_dev

void pcibios_disable_device (struct pci_dev *dev)
{
+ pcibios_disable_resources(dev);
if (pcibios_disable_irq)
pcibios_disable_irq(dev);
}
Index: linux-2.6.17-rc3-git7/arch/i386/pci/i386.c
===================================================================
--- linux-2.6.17-rc3-git7.orig/arch/i386/pci/i386.c
+++ linux-2.6.17-rc3-git7/arch/i386/pci/i386.c
@@ -242,6 +242,15 @@ int pcibios_enable_resources(struct pci_
return 0;
}

+void pcibios_disable_resources(struct pci_dev *dev)
+{
+ u16 cmd;
+
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
+ cmd &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
+ pci_write_config_word(dev, PCI_COMMAND, cmd);
+}
+
/*
* If we set up a device for bus mastering, we need to check the latency
* timer as certain crappy BIOSes forget to set it properly.
Index: linux-2.6.17-rc3-git7/arch/i386/pci/pci.h
===================================================================
--- linux-2.6.17-rc3-git7.orig/arch/i386/pci/pci.h
+++ linux-2.6.17-rc3-git7/arch/i386/pci/pci.h
@@ -35,6 +35,7 @@ extern unsigned int pcibios_max_latency;

void pcibios_resource_survey(void);
int pcibios_enable_resources(struct pci_dev *, int);
+void pcibios_disable_resources(struct pci_dev *);

/* pci-pc.c */

-
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