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authorjhb <jhb@FreeBSD.org>2012-03-01 20:36:50 +0000
committerjhb <jhb@FreeBSD.org>2012-03-01 20:36:50 +0000
commit20f70f7f55cbd6a05571983524a210f9ea3b7066 (patch)
treecaaac6451496eb3be3b4fa972802a24d4dabe933 /share
parente03043889a2018be37c98fc3a9d57843a4ab819a (diff)
downloadFreeBSD-src-20f70f7f55cbd6a05571983524a210f9ea3b7066.zip
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Update the documentation on pci_get/set_powerstate(). These methods are
not ACPI-specific at all, but deal with PCI power states. Also, pci_set_powerstate() fails with EOPNOTSUPP if a request is made that the underlying device does not support rather than falling back to somehow setting D0.
Diffstat (limited to 'share')
-rw-r--r--share/man/man9/pci.918
1 files changed, 8 insertions, 10 deletions
diff --git a/share/man/man9/pci.9 b/share/man/man9/pci.9
index 16cca62..37a4f9a 100644
--- a/share/man/man9/pci.9
+++ b/share/man/man9/pci.9
@@ -145,13 +145,13 @@ the configuration space.
.Pp
The
.Fn pci_get_powerstate
-function returns the current ACPI power state of the device
+function returns the current power state of the device
.Fa dev .
If the device does not support power management capabilities, then the default
state of
.Dv PCI_POWERSTATE_D0
is returned.
-The following power states are defined by ACPI:
+The following power states are defined by PCI:
.Bl -hang -width ".Dv PCI_POWERSTATE_UNKNOWN"
.It Dv PCI_POWERSTATE_D0
State in which device is on and running.
@@ -183,15 +183,13 @@ The
.Fn pci_set_powerstate
function is used to transition the device
.Fa dev
-to the ACPI power state
+to the PCI power state
.Fa state .
-It checks to see if the device is PCI 2.2 compliant.
-If so, it checks the
-capabilities pointer to determine which power states the device supports.
-If the device does not have power management capabilities, the default state
-of
-.Dv PCI_POWERSTATE_D0
-is set.
+If the device does not support power management capabilities or
+it does not support the specific power state
+.Fa state ,
+then the function will fail with
+.Er EOPNOTSUPP .
.Pp
The
.Fn pci_save_state
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