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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-02-07 10:46:30 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-02-07 10:46:30 -0800 |
commit | e83102cab0fd95d4508361b061146c978b3abd60 (patch) | |
tree | d1452292bf5d55da6a072d36d507d2e918ee2180 /Documentation | |
parent | 7f9a50a5b89b87f8e754f59ae9968da28be618a5 (diff) | |
parent | 5294e256717923f4a3297bb8b802f5e0625763f3 (diff) | |
download | linux-e83102cab0fd95d4508361b061146c978b3abd60.tar.bz2 |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI PM: make the PM core more careful with drivers using the new PM framework
PCI PM: Read power state from device after trying to change it on resume
PCI PM: Do not disable and enable bridges during suspend-resume
PCI: PCIe portdrv: Simplify suspend and resume
PCI PM: Fix saving of device state in pci_legacy_suspend
PCI PM: Check if the state has been saved before trying to restore it
PCI PM: Fix handling of devices without drivers
PCI: return error on failure to read PCI ROMs
PCI: properly clean up ASPM link state on device remove
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/filesystems/sysfs-pci.txt | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt index 68ef48839c04..9f8740ca3f3b 100644 --- a/Documentation/filesystems/sysfs-pci.txt +++ b/Documentation/filesystems/sysfs-pci.txt @@ -9,6 +9,7 @@ that support it. For example, a given bus might look like this: | |-- class | |-- config | |-- device + | |-- enable | |-- irq | |-- local_cpus | |-- resource @@ -32,6 +33,7 @@ files, each with their own function. class PCI class (ascii, ro) config PCI config space (binary, rw) device PCI device (ascii, ro) + enable Whether the device is enabled (ascii, rw) irq IRQ number (ascii, ro) local_cpus nearby CPU mask (cpumask, ro) resource PCI resource host addresses (ascii, ro) @@ -57,10 +59,19 @@ used to do actual device programming from userspace. Note that some platforms don't support mmapping of certain resources, so be sure to check the return value from any attempted mmap. +The 'enable' file provides a counter that indicates how many times the device +has been enabled. If the 'enable' file currently returns '4', and a '1' is +echoed into it, it will then return '5'. Echoing a '0' into it will decrease +the count. Even when it returns to 0, though, some of the initialisation +may not be reversed. + The 'rom' file is special in that it provides read-only access to the device's ROM file, if available. It's disabled by default, however, so applications should write the string "1" to the file to enable it before attempting a read -call, and disable it following the access by writing "0" to the file. +call, and disable it following the access by writing "0" to the file. Note +that the device must be enabled for a rom read to return data succesfully. +In the event a driver is not bound to the device, it can be enabled using the +'enable' file, documented above. Accessing legacy resources through sysfs ---------------------------------------- |