ata: make ata port as parent device of scsi host
authorLin Ming <ming.m.lin@intel.com>
Mon, 5 Dec 2011 01:20:23 +0000 (09:20 +0800)
committerJeff Garzik <jgarzik@redhat.com>
Mon, 9 Jan 2012 00:14:57 +0000 (19:14 -0500)
commit9a6d6a2ddabbd32c07f6a38b659e5f3db319fa5a
tree4501e80654ad8adb928ec575f2cd866c15ba87db
parent7faa33da9b7add01db9f1ad92c6a5d9145e940a7
ata: make ata port as parent device of scsi host

Currently, the device tree of ata port and scsi host looks as below,

        /sys/devices/pci0000:00/0000:00:1f.2    (ahci controller)
        |-- ata1                                (ata port)
        |-- host0                               (scsi host)
           |-- target0:0:0                      (scsi target)
               |-- 0:0:0:0                      (disk)

This patch makes ata port as parent device of scsi host, then it becomes

        /sys/devices/pci0000:00/0000:00:1f.2    (ahci controller)
        |-- ata1                                (ata port)
            |-- host0                           (scsi host)
                |-- target0:0:0                 (scsi target)
                    |-- 0:0:0:0                 (disk)

With this change, the ata port runtime PM is easier.
For example, the ata port runtime suspend will happen as,

disk suspend --> scsi target suspend --> scsi host suspend --> ata port
suspend.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
drivers/ata/libata-scsi.c