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authorLinus Torvalds <torvalds@linux-foundation.org>2009-02-07 13:46:30 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-02-07 13:46:30 -0500
commite83102cab0fd95d4508361b061146c978b3abd60 (patch)
treed1452292bf5d55da6a072d36d507d2e918ee2180 /Documentation
parent7f9a50a5b89b87f8e754f59ae9968da28be618a5 (diff)
parent5294e256717923f4a3297bb8b802f5e0625763f3 (diff)
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.txt13
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:
9 | |-- class 9 | |-- class
10 | |-- config 10 | |-- config
11 | |-- device 11 | |-- device
12 | |-- enable
12 | |-- irq 13 | |-- irq
13 | |-- local_cpus 14 | |-- local_cpus
14 | |-- resource 15 | |-- resource
@@ -32,6 +33,7 @@ files, each with their own function.
32 class PCI class (ascii, ro) 33 class PCI class (ascii, ro)
33 config PCI config space (binary, rw) 34 config PCI config space (binary, rw)
34 device PCI device (ascii, ro) 35 device PCI device (ascii, ro)
36 enable Whether the device is enabled (ascii, rw)
35 irq IRQ number (ascii, ro) 37 irq IRQ number (ascii, ro)
36 local_cpus nearby CPU mask (cpumask, ro) 38 local_cpus nearby CPU mask (cpumask, ro)
37 resource PCI resource host addresses (ascii, ro) 39 resource PCI resource host addresses (ascii, ro)
@@ -57,10 +59,19 @@ used to do actual device programming from userspace. Note that some platforms
57don't support mmapping of certain resources, so be sure to check the return 59don't support mmapping of certain resources, so be sure to check the return
58value from any attempted mmap. 60value from any attempted mmap.
59 61
62The 'enable' file provides a counter that indicates how many times the device
63has been enabled. If the 'enable' file currently returns '4', and a '1' is
64echoed into it, it will then return '5'. Echoing a '0' into it will decrease
65the count. Even when it returns to 0, though, some of the initialisation
66may not be reversed.
67
60The 'rom' file is special in that it provides read-only access to the device's 68The 'rom' file is special in that it provides read-only access to the device's
61ROM file, if available. It's disabled by default, however, so applications 69ROM file, if available. It's disabled by default, however, so applications
62should write the string "1" to the file to enable it before attempting a read 70should write the string "1" to the file to enable it before attempting a read
63call, and disable it following the access by writing "0" to the file. 71call, and disable it following the access by writing "0" to the file. Note
72that the device must be enabled for a rom read to return data succesfully.
73In the event a driver is not bound to the device, it can be enabled using the
74'enable' file, documented above.
64 75
65Accessing legacy resources through sysfs 76Accessing legacy resources through sysfs
66---------------------------------------- 77----------------------------------------