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 v4 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 /sys/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/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 suspended And if you do some IO, it will resume immediately. v4: - add CONFIG_PM_RUNTIME check - 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 v3: - remove block layer suspend/resume callbacks - add block layer runtime pm helper functions v2: - 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 | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ block/elevator.c | 13 +++++++++++++ drivers/scsi/scsi_lib.c | 25 ++++++++++++++++++++++--- drivers/scsi/scsi_pm.c | 32 +++++++++++++++++++++++++------- drivers/scsi/scsi_sysfs.c | 2 ++ drivers/scsi/sd.c | 16 +++++----------- include/linux/blk_types.h | 2 ++ include/linux/blkdev.h | 27 +++++++++++++++++++++++++++ include/scsi/scsi_device.h | 4 ++++ 9 files changed, 179 insertions(+), 21 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
