Re: [PATCH v4 2/3] dt-bindings: usb: snps,dwc3: Add runtime-suspend-on-usb-suspend property

[Elson Serrao]

On 8/15/2023 10:44 PM, Krzysztof Kozlowski wrote:
> On 14/08/2023 20:50, Elson Roy Serrao wrote:
> > This property allows dwc3 runtime suspend when bus suspend interrupt
> > is received even with cable connected. This would allow the dwc3
> > controller to enter low power mode during bus suspend scenario.
> >
> > This property would particularly benefit dwc3 IPs where hibernation is
> > not enabled and the dwc3 low power mode entry/exit is handled by the
> > glue driver. The assumption here is that the platform using this dt
> > property is capable of detecting resume events to bring the controller
> > out of suspend.
> >
> > Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
> > ---
> >   Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > index a696f23730d3..e19a60d06d2b 100644
> > --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > @@ -403,6 +403,11 @@ properties:
> >       description:
> >         Enable USB remote wakeup.
> >   
> > +  snps,runtime-suspend-on-usb-suspend:
> > +    description:
> > +      If True then dwc3 runtime suspend is allowed during bus suspend
> > +      case even with the USB cable connected.
>
> This was no tested... but anyway, this is no a DT property but OS
> policy. There is no such thing as "runtime suspend" in the hardware,
> because you describe one particular OS.
>
> Sorry, no a DT property, drop the change entirely.
Hi Krzysztof

Sorry my local dt checker had some issue and it did not catch these 
errors. I have rectified it now.

This dt property is mainly for skipping dwc3 controller halt when a USB 
suspend interrupt is received with usb cable connected, so that we dont 
trigger a DISCONNECT event. Perhaps a better name would reflect the true 
usage of this?

Something like snps,skip-dwc3-halt-on-usb-suspend. dwc3 cores where 
hibernation feature is not enabled/supported can use this property

Hi Thinh,Roger
Please let me know your opinion on 'snps,skip-dwc3-halt-on-usb-suspend' 
as the quirk name.

Thanks
Elson