This add a very conservative implementation of runtime PM to the sd scsi driver: Resume when opened (mounted) and suspend when released (unmounted).
often event polling for block devicesneeds to be disabled in order to be able to suspend: echo 0 > /sys/module/block/parameters/events_dfl_poll_msecs
This still doesn't enable runtime PM by default. It can be enabled via the standard Linux power user interface, like: echo 1000 > /sys/bus/scsi/devices/0:0:0:0/power/autosuspend_delay_ms echo auto > /sys/bus/scsi/devices/0:0:0:0/power/control
Signed-off-by: Martin Kepplinger email@example.com