Re: [PATCH v11 13/13] arm64: dts: qcom: sa8540-ride: Enable first port of tertiary usb controller

[Konrad Dybcio]

On 9/14/23 17:45, Krishna Kurapati PSSNV wrote:
> On 9/13/2023 5:40 PM, Konrad Dybcio wrote:
> > On 7.09.2023 05:36, Krishna Kurapati PSSNV wrote:
> > > > Is there any benefit to removing the other ports?
> > > >
> > > > i.e. are ports 1-3 not parked properly by the dwc3 driver if
> > > > they're never connected to anything?
> > > Hi Konrad,
> > >
> > >   Whether or not the phy is connected to a port, the controller would 
> > > modify the GUSB2PHYCFG/GUSB3PIPECTL registers. But if we don't 
> > > specify only one phy and let phys from base DTSI take effect (4 HS / 
> > > 2 SS), we would end up initializing and powering on phy's which are 
> > > never connected to a port. To avoid that we need to specify only one 
> > > phy for this platform.
> > And does that have any major effect on power use?
> >
> > Do these PHYs not have some dormant/low power mode?
> Hi Konrad,
>
>   I believe there will be some minimal power use. IMO its best to keep 
> only one phy enabled for this variant instead of giving all and 
> initializing/powering-on all 4 of them.
Okay let's not waste power..

Konrad