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[PATCH] PCI: clean up pci documentation to be more specific
On Thu, Jun 01, 2006 at 02:46:11AM -0700, Rajesh Shah wrote: > This patch assumes that pci_request_region() will always be called > after pci_enable_device() and pci_release_region() will always > be called before pci_disable_device(). We cannot make this > assumption,since it's perfectly legal to disable a device > first and then release it's regions. So, I think that patch > needs to change. Patch below clarifies comments in Documentation/pci.txt. Signed-off-by: Grant Grundler <grundler@parisc-linux.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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@ -213,9 +213,17 @@ have been remapped by the kernel.
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See Documentation/IO-mapping.txt for how to access device memory.
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You still need to call request_region() for I/O regions and
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request_mem_region() for memory regions to make sure nobody else is using the
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same device.
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The device driver needs to call pci_request_region() to make sure
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no other device is already using the same resource. The driver is expected
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to determine MMIO and IO Port resource availability _before_ calling
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pci_enable_device(). Conversely, drivers should call pci_release_region()
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_after_ calling pci_disable_device(). The idea is to prevent two devices
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colliding on the same address range.
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Generic flavors of pci_request_region() are request_mem_region()
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(for MMIO ranges) and request_region() (for IO Port ranges).
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Use these for address resources that are not described by "normal" PCI
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interfaces (e.g. BAR).
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All interrupt handlers should be registered with SA_SHIRQ and use the devid
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to map IRQs to devices (remember that all PCI interrupts are shared).
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