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authorGrant Grundler <grundler@parisc-linux.org>2006-06-01 13:15:59 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2006-06-21 15:00:00 -0400
commit733a7fe12248072e1bca729c88a26298666f1956 (patch)
tree059c803091394a3a61a6c4537a4eaa3f5426fa5f /Documentation/pci.txt
parentf7e6600d762bf7c04b48c8d9bd0ab26d04a8d11f (diff)
[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>
Diffstat (limited to 'Documentation/pci.txt')
-rw-r--r--Documentation/pci.txt14
1 files changed, 11 insertions, 3 deletions
diff --git a/Documentation/pci.txt b/Documentation/pci.txt
index 66bbbf1d1ef6..3242e5c1ee9c 100644
--- a/Documentation/pci.txt
+++ b/Documentation/pci.txt
@@ -213,9 +213,17 @@ have been remapped by the kernel.
213 213
214 See Documentation/IO-mapping.txt for how to access device memory. 214 See Documentation/IO-mapping.txt for how to access device memory.
215 215
216 You still need to call request_region() for I/O regions and 216 The device driver needs to call pci_request_region() to make sure
217request_mem_region() for memory regions to make sure nobody else is using the 217no other device is already using the same resource. The driver is expected
218same device. 218to determine MMIO and IO Port resource availability _before_ calling
219pci_enable_device(). Conversely, drivers should call pci_release_region()
220_after_ calling pci_disable_device(). The idea is to prevent two devices
221colliding on the same address range.
222
223Generic flavors of pci_request_region() are request_mem_region()
224(for MMIO ranges) and request_region() (for IO Port ranges).
225Use these for address resources that are not described by "normal" PCI
226interfaces (e.g. BAR).
219 227
220 All interrupt handlers should be registered with SA_SHIRQ and use the devid 228 All interrupt handlers should be registered with SA_SHIRQ and use the devid
221to map IRQs to devices (remember that all PCI interrupts are shared). 229to map IRQs to devices (remember that all PCI interrupts are shared).