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author | Grant Grundler <grundler@parisc-linux.org> | 2006-06-01 11:15:59 -0600 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-06-21 12:00:00 -0700 |
commit | 733a7fe12248072e1bca729c88a26298666f1956 (patch) | |
tree | 059c803091394a3a61a6c4537a4eaa3f5426fa5f /Documentation/pci.txt | |
parent | f7e6600d762bf7c04b48c8d9bd0ab26d04a8d11f (diff) | |
download | linux-733a7fe12248072e1bca729c88a26298666f1956.tar.bz2 |
[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.txt | 14 |
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. See Documentation/IO-mapping.txt for how to access device memory. - You still need to call request_region() for I/O regions and -request_mem_region() for memory regions to make sure nobody else is using the -same device. + The device driver needs to call pci_request_region() to make sure +no other device is already using the same resource. The driver is expected +to determine MMIO and IO Port resource availability _before_ calling +pci_enable_device(). Conversely, drivers should call pci_release_region() +_after_ calling pci_disable_device(). The idea is to prevent two devices +colliding on the same address range. + +Generic flavors of pci_request_region() are request_mem_region() +(for MMIO ranges) and request_region() (for IO Port ranges). +Use these for address resources that are not described by "normal" PCI +interfaces (e.g. BAR). All interrupt handlers should be registered with SA_SHIRQ and use the devid to map IRQs to devices (remember that all PCI interrupts are shared). |