Re: [PATCH] Revert "usb: cdns3: core: quit if it uses role switch class"

[Roger Quadros]

Peter,

On 24/11/2020 13:47, Peter Chen wrote:
> On 20-11-24 12:33:34, Roger Quadros wrote:
> > > > > I am sorry about that. Do you use role switch /sys entry, if you have
> > > > > used, I prefer using "usb-role-switch" property at dts to judge if SoC
> > > > > OTG signals or external signals for role switch. If you have not used
> > > > > it, I prefer only setting cdns->role_sw for role switch use cases.
> > > >
> > > > We use both hardware role switch and /sys entries for manually forcing a
> > > > certain role.
> > > >
> > > > We do not set any "usb-role-switch" property at DTS.
> > > >
> > > > Currently cdns->role_sw is being always set by driver irrespective of any DT
> > > > property, so this patch is clearly wrong and needs to be reverted.
> > > >
> > > > What do you think?
> > >
> > > Could you accept below fix?
> > >
> > > diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
> > > index 2e469139769f..fdd52e87a7b2 100644
> > > --- a/drivers/usb/cdns3/core.c
> > > +++ b/drivers/usb/cdns3/core.c
> > > @@ -280,8 +280,8 @@ int cdns3_hw_role_switch(struct cdns3 *cdns)
> > >           enum usb_role real_role, current_role;
> > >           int ret = 0;
> > >
> > > -       /* Depends on role switch class */
> > > -       if (cdns->role_sw)
> > > +       /* quit if switch role through external signals */
> > > +       if (device_property_read_bool(cdns->dev, "usb-role-switch"))
> > >                   return 0;
> > >
> > >           pm_runtime_get_sync(cdns->dev);
> >
> > Although this will fix the issue I don't think this is making the driver to behave
> > as expected with usb-role-switch property.
> >
> > Now, even if usb-role-switch property is not present the driver will still register
> > the role switch driver.
> >
> > I think we need to register the role switch driver only if usb-role-switch property
> > is present. We would also need to set the default role if role-switch-default-mode is present.
> >
> > How about the following? It still doesn't handle role-switch-default-mode property though.
>
> Roger, you said you also use /sys entries (I suppose it means through role
> switch class) to do role switch, with your change, there will be no /sys
> entry for role switch.

Sorry for the confusion. Although we do need both features (SW role switch + HW role switch)
I don't think it is required to operate simultaneously. If users need SW control they can set the DT flag.

cheers,
-roger

> Peter
>
> > > > We use both hardware role switch and /sys entries for manually forcing a
> > > > certain role.
>
>
>
>
> > diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
> > index 4c1445cf2ad0..986b56a9940c 100644
> > --- a/drivers/usb/cdns3/core.c
> > +++ b/drivers/usb/cdns3/core.c
> > @@ -532,11 +532,13 @@ static int cdns3_probe(struct platform_device *pdev)
> >   	if (device_property_read_bool(dev, "usb-role-switch"))
> >   		sw_desc.fwnode = dev->fwnode;
> > -	cdns->role_sw = usb_role_switch_register(dev, &sw_desc);
> > -	if (IS_ERR(cdns->role_sw)) {
> > -		ret = PTR_ERR(cdns->role_sw);
> > -		dev_warn(dev, "Unable to register Role Switch\n");
> > -		goto err3;
> > +	if (device_property_read_bool(cdns->dev, "usb-role-switch")) {
> > +		cdns->role_sw = usb_role_switch_register(dev, &sw_desc);
> > +		if (IS_ERR(cdns->role_sw)) {
> > +			ret = PTR_ERR(cdns->role_sw);
> > +			dev_warn(dev, "Unable to register Role Switch\n");
> > +			goto err3;
> > +		}
> >   	}
> >   	if (cdns->wakeup_irq) {
> >
> >
> >
> > cheers,
> > -roger
> > --
> > Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> > Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki