Re: [PATCH V4 2/4] arm64: dts: qcom: sc7180: Improve the pin config settings for CTS and TX

[skakit]

Hi Doug,

On 2020-09-10 02:58, Doug Anderson wrote:
> Hi,
>
> On Thu, Sep 3, 2020 at 8:07 AM satya priya <skakit@xxxxxxxxxxxxxx> 
> wrote:
> > --- a/arch/arm64/boot/dts/qcom/sc7180-idp.dts
> > +++ b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
> > @@ -474,32 +474,30 @@
> >  &qup_uart3_default {
> >         pinconf-cts {
> >                 /*
> > -                * Configure a pull-down on 38 (CTS) to match the pull 
> > of
> > -                * the Bluetooth module.
> > +                * Configure no-pull on CTS. As this is driven by BT, 
> > do not
> > +                * specify any pull in order to not conflict with BT 
> > pulls.
> >                  */
> >                 pins = "gpio38";
> > -               bias-pull-down;
> > -               output-high;
>
> Weird, how did that output-high sneak in there?  Glad it's going away.
>
>
> > +               bias-disable;
>
> I'm not convinced that the removal of the pul is the correct thing
> here.  Specifically for the rx line the comment makes the argument
> that if we power off the Bluetooth module then it will stop driving
> this pin.  In that case if we remove the pull here then the line will
> be floating and that can cause some extra power consumption as the
> line floats between different logic levels.  Do you really need to
> remove this pull?

Okay, will keep the pull-down back for CTS.

> Same comment for the next patch where you add the sleep settings.
>
>
> -Doug