• Aaron Lu's avatar
    ata: acpi: rework the ata acpi bind support · f1bc1e4c
    Aaron Lu authored
    Binding ACPI handle to SCSI device has several drawbacks, namely:
    1 During ATA device initialization time, ACPI handle will be needed
      while SCSI devices are not created yet. So each time ACPI handle is
      needed, instead of retrieving the handle by ACPI_HANDLE macro,
      a namespace scan is performed to find the handle for the corresponding
      ATA device. This is inefficient, and also expose a restriction on
      calling path not holding any lock.
    2 The binding to SCSI device tree makes code complex, while at the same
      time doesn't bring us any benefit. All ACPI handlings are still done
      in ATA module, not in SCSI.
    
    Rework the ATA ACPI binding code to bind ACPI handle to ATA transport
    devices(ATA port and ATA device). The binding needs to be done only once,
    since the ATA transport devices do not go away with hotplug. And due to
    this, the flush_work call in hotplug handler for ATA bay is no longer
    needed.
    
    Tested on an Intel test platform for binding and runtime power off for
    ODD(ZPODD) and hard disk; on an ASUS S400C for binding and normal boot
    and S3, where its SATA port node has _SDD and _GTF control methods when
    configured as an AHCI controller and its PATA device node has _GTF
    control method when configured as an IDE controller. SATA PMP binding
    and ATA hotplug is not tested.
    Signed-off-by: default avatarAaron Lu <aaron.lu@intel.com>
    Tested-by: default avatarDirk Griesbach <spamthis@freenet.de>
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    f1bc1e4c
libata-scsi.c 104 KB