Terminate the Capability List traversal if the Capability Pointer is less than 0x40...

[mirror_edk2.git] / IntelFrameworkModulePkg / Bus / Pci / PciBusDxe / PciPowerManagement.c

/** @file\r
\r
Copyright (c) 2006, Intel Corporation                                                         \r
All rights reserved. This program and the accompanying materials                          \r
are licensed and made available under the terms and conditions of the BSD License         \r
which accompanies this distribution.  The full text of the license may be found at        \r
http://opensource.org/licenses/bsd-license.php                                            \r
                                                                                          \r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     \r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             \r
\r
**/\r
\r
#include "PciBus.h"\r
\r
/**\r
  This function is intended to turn off PWE assertion and\r
  put the device to D0 state if the device supports\r
  PCI Power Management.\r
\r
  @param PciIoDevice  Pci device instance\r
\r
  @retval EFI_UNSUPPORTED Device do not support power management\r
  @retval EFI_SUCCESS     Success\r
**/\r
EFI_STATUS\r
ResetPowerManagementFeature (\r
  IN PCI_IO_DEVICE *PciIoDevice\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINT8       PowerManagementRegBlock;\r
  UINT16      PowerManagementCSR;\r
\r
  PowerManagementRegBlock = 0;\r
\r
  Status = LocateCapabilityRegBlock (\r
            PciIoDevice,\r
            EFI_PCI_CAPABILITY_ID_PMI,\r
            &PowerManagementRegBlock,\r
            NULL\r
            );\r
\r
  if (EFI_ERROR (Status)) {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  //\r
  // Turn off the PWE assertion and put the device into D0 State\r
  //\r
  PowerManagementCSR = 0x8000;\r
\r
  //\r
  // Write PMCSR\r
  //\r
  PciIoWrite (\r
               &PciIoDevice->PciIo,\r
               EfiPciIoWidthUint16,\r
               PowerManagementRegBlock + 4,\r
               1,\r
               &PowerManagementCSR\r
             );\r
\r
  return EFI_SUCCESS;\r
}\r
\r