Re: [PATCH] scsi: ufs-qcom: add number of lanes per direction

[cang]

On 2018-02-09 10:29, Rob Herring wrote:
> On Mon, Feb 05, 2018 at 08:02:07PM +0800, Can Guo wrote:
> > From: Gilad Broner <gbroner@xxxxxxxxxxxxxx>
> >
> > Different platforms may have different number of lanes for the UFS 
> > link.
> > Add parameter to device tree specifying how many lanes should be
> > configured for the UFS link. And don't print err message for clocks
> > that are optional, this leads to unnecessary confusion about failure.
> >
> > Signed-off-by: Gilad Broner <gbroner@xxxxxxxxxxxxxx>
> > Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
> > Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> >
> > diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt 
> > b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> > index 5357919..4cee3f9 100644
> > --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> > +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> > @@ -31,6 +31,9 @@ Optional properties:
> >  			  defined or a value in the array is "0" then it is assumed
> >  			  that the frequency is set by the parent clock or a
> >  			  fixed rate clock source.
> > +- 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.
>
> Seems reasonable until someone does not make things symmetrical. We
> should design for that case.
You are right, I will make changes like using lanes-tx and lanes-rx for 
Tx/Rx links for asymmetrial senarios and upload V2 patch
> > +			If not specified, default is 2 lanes per direction.
> >
> >  Note: If above properties are not defined it can be assumed that the 
> > supply
> >  regulators or clocks are always on.