[PATCH v2 0/4] ata port runtime power management support
From: Lin Ming
Date: Thu Nov 10 2011 - 01:23:04 EST
Hi, all
These 4 patches add ata port runtime pm support.
v1:
https://lkml.org/lkml/2011/11/2/23
v2 is totally different than v1.
v1 performed ata port runtime pm through scsi layer.
Added hook to scsi host runtime suspend/resume code.
I realized that this is not the natural way to do ata port runtime pm.
It does not deal with the races with ata port system suspend/resume.
With v2, ata port is made to be 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)
v2 changes it to:
/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)
So ata port runtime PM will happen as:
disk suspend --> scsi target suspend --> scsi host suspend --> ata port
suspend.
This is much cleaner and natural.
Lin Ming (4):
ata: make ata port as parent device of scsi host
scsi: add flag to skip the runtime PM calls on host in EH
ata: add ata port system PM callbacks
ata: add ata port runtime PM callbacks
drivers/ata/libata-core.c | 158 ++++++++++++++++++++++------------------
drivers/ata/libata-scsi.c | 3 +-
drivers/ata/libata-transport.c | 5 +
drivers/ata/libata.h | 1 +
drivers/scsi/scsi_error.c | 5 +-
include/scsi/scsi_host.h | 3 +
6 files changed, 102 insertions(+), 73 deletions(-)
Thanks for any comment.
Lin Min
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