1. 07 10月, 2012 1 次提交
    • L
      ACPI: Add new sysfs interface to export device description · d1efe3c3
      Lance Ortiz 提交于
      Add support to export the device description obtained from the ACPI _STR
      method, if one exists for a device, to user-space via a sysfs interface.
      This new interface provides a standard and platform neutral way for users
      to obtain the description text stored in the ACPI _STR method.  If no
      _STR method exists for the device, no sysfs 'description' file will be
      created.  The 'description' file will be located in the /sys/devices/
      directory using the device's path.
      
      /sys/device/<bus>/<bridge path>/<device path>.../firmware_node/description
      
      Example:
      
      /sys/devices/pci0000:00/0000:00.07.0/0000:0e:00.0/firmware_node/description
      
      It can also be located using the ACPI device path, for example:
      
      /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/device:15/description
      /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/description
      
      Execute the 'cat' command on the 'description' file to obtain the
      description string for that device.
      
      This patch also includes documentation describing how the new sysfs
      interface works
      
      Changes from v1-v2 based on comments by Len Brown and Fengguang Wu
      * Removed output "No Description" and leaving a NULL attribute if the
      _STR method failed to evaluate.
      
      * In acpi_device_remove_files() removed the redundent check of
      dev->pnp.str_obj before calling free.  This check triggered a message
      from smatch.
      Signed-off-by: NLance Ortiz <lance.ortiz@hp.com>
      Signed-off-by: NLen Brown <len.brown@intel.com>
      d1efe3c3