svn commit: r232363 - head/share/man/man9

[John Baldwin]

Author: jhb
Date: Thu Mar  1 20:36:50 2012
New Revision: 232363
URL: http://svn.freebsd.org/changeset/base/232363

Log:
  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.

Modified:
  head/share/man/man9/pci.9

Modified: head/share/man/man9/pci.9
==============================================================================
--- head/share/man/man9/pci.9	Thu Mar  1 20:32:02 2012	(r232362)
+++ head/share/man/man9/pci.9	Thu Mar  1 20:36:50 2012	(r232363)
@@ -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