Until now the scsi mid-layer forbids runtime suspend till userspace enables it.
This is mainly to quarantine some disks with broken runtime power management or
have high latencies executing suspend resume callbacks. If the userspace
doesn't enable the runtime suspend the underlying hardware will be always on
even when it is not doing any useful work and thus wasting power.
Some low-level drivers for the controllers can efficiently use runtime power
management to reduce power consumption and improve battery life.
This patchset allows runtime suspend parameters override within the LLD itself
instead of waiting for userspace to control the power management, and make UFS
as the first user of this capability.
v3 => v4:
- Change scsi_device->rpm_autosuspend_on to scsi_device->rpm_autosuspend (Bart)
- Make the comment of scsi_device->rpm_autosuspend more elaborate (Bart)
v2 => v3:
- Create a member indicating autosuspend delay for the same SCSI host in SCSI
host template (Bart)
- Use separate variables to control different things, (Bart)
(a) Whether or not runtime suspend is enabled at device creation time
(b) The power management autosuspend delay
v1 => v2:
- Allow "zero" sdev->rpm_autosuspend_delay (Avri)
- Fix format of some lines (Avri)
Stanley Chu (3):
scsi: core: allow auto suspend override by low-level driver
scsi: ufs: override auto suspend tunables for ufs
scsi: ufs-mediatek: enable auto suspend capability
drivers/scsi/scsi_sysfs.c | 3 ++-
drivers/scsi/sd.c | 4 ++++
drivers/scsi/ufs/ufs-mediatek.c | 3 +++
drivers/scsi/ufs/ufshcd.c | 9 +++++++++
drivers/scsi/ufs/ufshcd.h | 10 ++++++++++
include/scsi/scsi_device.h | 3 ++-
include/scsi/scsi_host.h | 3 +++
7 files changed, 33 insertions(+), 2 deletions(-)
--
2.18.0
