[PATCH v5 0/4] block layer runtime pm

From: Lin Ming
Date: Fri Jul 06 2012 - 00:04:33 EST

In August 2010, Jens and Alan discussed about "Runtime PM and the block
layer". http://marc.info/?t=128259108400001&r=1&w=2

Here are the v5 patches to implement the ideas discussed.
Welcome to give it a try.

git pull git://git.kernel.org/pub/scm/linux/kernel/git/mlin/linux.git block_pm

The test steps, for example

# ls -l /sys/block/sda

# echo auto > /sys/devices/pci0000:00/0000:00:1f.2/ata1/power/control
# echo auto > /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/power/control
# echo 10000 > /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/power/autosuspend_delay_ms

Then you'll see sda is suspended after 10secs idle.

# cat /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/power/runtime_status

And if you do some IO, it will resume immediately.

- rename scsi_execute_req to scsi_execute_req_flags
and wrap scsi_execute_req around it.
- add detail function descriptions in patch 2 log
- define static helper functions to do runtime pm work on block layer
and put the definitions inside a #ifdef block

- update queue runtime pm status after system resume
- use pm_runtime_autosuspend instead of pm_request_autosuspend in scsi_runtime_idle
- always count PM request

- remove block layer suspend/resume callbacks
- add block layer runtime pm helper functions

- remove queue idle timer, use runtime pm core's auto suspend

Lin Ming (4):
block: add a flag to identify PM request
block: add runtime pm helpers
block: implement runtime pm strategy
[SCSI] sd: change to auto suspend mode

block/blk-core.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
block/elevator.c | 4 ++++
drivers/scsi/scsi_lib.c | 9 ++++-----
drivers/scsi/scsi_pm.c | 38 ++++++++++++++++++++++++++++++--------
drivers/scsi/scsi_sysfs.c | 2 ++
drivers/scsi/sd.c | 16 +++++-----------
include/linux/blk_types.h | 2 ++
include/linux/blkdev.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
include/scsi/scsi_device.h | 17 +++++++++++++----
9 files changed, 194 insertions(+), 28 deletions(-)
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