On Mon, Dec 12, 2016 at 04:54:20PM -0800, Subhash Jadavani wrote: > UFS device and link can be put in multiple different low power modes hence > UFS driver supports multiple different low power modes. By default UFS > driver selects the default (optimal) low power mode (which gives moderate > power savings and have relatively less enter and exit latencies) but > we might have to tune this default power mode for different chipset > platforms to meet the low power requirements/goals. Hence this patch > adds option to change default UFS low power mode (level). > > Reviewed-by: Yaniv Gardi <yga...@codeaurora.org> > Signed-off-by: Subhash Jadavani <subha...@codeaurora.org> > --- > .../devicetree/bindings/ufs/ufshcd-pltfrm.txt | 10 ++++++ > drivers/scsi/ufs/ufshcd-pltfrm.c | 14 ++++++++ > drivers/scsi/ufs/ufshcd.c | 39 > ++++++++++++++++++++++ > drivers/scsi/ufs/ufshcd.h | 4 +-- > 4 files changed, 65 insertions(+), 2 deletions(-) > > diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > index a99ed55..c3836c5 100644 > --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt > @@ -41,6 +41,14 @@ Optional properties: > -lanes-per-direction : number of lanes available per direction - either 1 or > 2. > Note that it is assume same number of lanes is used > both > directions at once. If not specified, default is 2 > lanes per direction. > +- rpm-level : UFS Runtime power management level. Following PM > levels are supported: > + 0 - Both UFS device and Link in active state (Highest > power consumption) > + 1 - UFS device in active state but Link in Hibern8 > state > + 2 - UFS device in Sleep state but Link in active state > + 3 - UFS device in Sleep state and Link in hibern8 > state (default PM level) > + 4 - UFS device in Power-down state and Link in > Hibern8 state > + 5 - UFS device in Power-down state and Link in OFF > state (Lowest power consumption) > +- spm-level : UFS System power management level. Allowed PM levels > are same as rpm-level.
This looks like you are putting policy for Linux into DT. What I would expect to see here is disabling of states that don't work due to some h/w limitation. Otherwise, it is a user decision for what modes to go into. Also, I think link and device states should be separate. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
