Re: [PATCH v2 2/2] usb: dwc2: prevent core PHY initialization on Rockchip

[Quentin Schulz]

Hi Minas,

On 12/20/22 07:02, Minas Harutyunyan wrote:
> Hi Quentin,
>
> On 12/16/2022 8:29 PM, Quentin Schulz <foss+kernel@xxxxxxxxx> wrote:
> > From: Quentin Schulz <foss+kernel@xxxxxxxxx>
> > Sent: Friday, December 16, 2022 8:29 PM
> > To: Minas Harutyunyan <hminas@xxxxxxxxxxxx>; Greg Kroah-Hartman
> > <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Quentin Schulz <foss+kernel@xxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx;
> > linux-kernel@xxxxxxxxxxxxxxx; Bin Yang <yangbin@xxxxxxxxxxxxxx>; Quentin
> > Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx>
> > Subject: [PATCH v2 2/2] usb: dwc2: prevent core PHY initialization on
> > Rockchip
> >
> > From: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx>
> >
> > In Rockchip vendor kernel, the core PHY initialization is disabled with the
> > following justification:
> >
> > The usb phys need to be controlled dynamically on some Rockchip SoCs.
> > So set the new HCD flag which prevents USB core from trying to manage  our
> > phys.
> >
> > This is required to get USB gadget working in dual-role mode on Ringneck
> > PX30 SoM on a Haikou Devkit.
> >
> > Cc: Bin Yang <yangbin@xxxxxxxxxxxxxx>
> > Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/usb/dwc2/params.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c index
> > 9ed9fd956940..9095437b3236 100644
> > --- a/drivers/usb/dwc2/params.c
> > +++ b/drivers/usb/dwc2/params.c
> > @@ -117,6 +117,7 @@ static void dwc2_set_rk_params(struct dwc2_hsotg *hsotg)
> > 	p->lpm_clock_gating = false;
> > 	p->besl = false;
> > 	p->hird_threshold_en = false;
> > +	p->hcd_skip_phy_initialization = 1;
>
> I'm not familiar with all "rk" platforms, but are you sure that
> p->hcd_skip_phy_initialization = 1 required for all of them?

No I am not. This is however applied to all devices (even non-Rockchip 
ones) in Rockchip vendor kernel.

I could check on an RK3368 since we have a module available for that, 
but I don't have access to any other Rockchip platform. From a quick 
grep, the following seems to be susceptible to this change:

rk3128
rv1108
rk3288
rk3036
rk3228-evb
rk3229
rk3066a
rk3188
rk3328
px30
rk3308
rk3368

Cheers,
Quentin