linux-kernel - Re: [PATCH v3 1/5] usb: typec: Add mode

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Message-ID: <CAMMMRMcqty7dC=UvwNZX90iVMnJATTPWYTf1fiee5_OoKfxSJA@mail.gmail.com>
Date: Wed, 10 Sep 2025 19:34:55 +0000
From: Andrei Kuchynski <akuchynski@...omium.org>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus@...ux.intel.com>, 
	Abhishek Pandit-Subedi <abhishekpandit@...omium.org>, Benson Leung <bleung@...omium.org>, 
	Jameson Thies <jthies@...gle.com>, Tzung-Bi Shih <tzungbi@...nel.org>, linux-usb@...r.kernel.org, 
	chrome-platform@...ts.linux.dev, Guenter Roeck <groeck@...omium.org>, 
	Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>, "Christian A. Ehrhardt" <lk@...e.de>, 
	Venkat Jayaraman <venkat.jayaraman@...el.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 1/5] usb: typec: Add mode_control field to port property

On Wed, Sep 10, 2025 at 1:30 PM Greg Kroah-Hartman
<gregkh@...uxfoundation.org> wrote:
>
> On Fri, Sep 05, 2025 at 02:22:02PM +0000, Andrei Kuchynski wrote:
> > This new field in the port properties dictates whether the Platform Policy
> > Manager (PPM) allows the OS Policy Manager (OPM) to change the currently
> > active, negotiated alternate mode.
> >
> > Signed-off-by: Andrei Kuchynski <akuchynski@...omium.org>
> > ---
> >  drivers/usb/typec/class.c | 9 ++++++---
> >  drivers/usb/typec/class.h | 2 ++
> >  include/linux/usb/typec.h | 2 ++
> >  3 files changed, 10 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> > index 67a533e35150..9f86605ce125 100644
> > --- a/drivers/usb/typec/class.c
> > +++ b/drivers/usb/typec/class.c
> > @@ -457,11 +457,13 @@ static umode_t typec_altmode_attr_is_visible(struct kobject *kobj,
> >                                            struct attribute *attr, int n)
> >  {
> >       struct typec_altmode *adev = to_typec_altmode(kobj_to_dev(kobj));
> > +     struct typec_port *port = typec_altmode2port(adev);
> >
> >       if (attr == &dev_attr_active.attr)
> > -             if (!is_typec_port(adev->dev.parent) &&
> > -                 (!adev->ops || !adev->ops->activate))
> > -                     return 0444;
> > +             if (!is_typec_port(adev->dev.parent)) {
> > +                     if (!port->mode_control || !adev->ops || !adev->ops->activate)
> > +                             return 0444;
> > +             }
> >
> >       return attr->mode;
> >  }
> > @@ -2681,6 +2683,7 @@ struct typec_port *typec_register_port(struct device *parent,
> >       }
> >
> >       port->pd = cap->pd;
> > +     port->mode_control = !cap->no_mode_control;
> >
> >       ret = device_add(&port->dev);
> >       if (ret) {
> > diff --git a/drivers/usb/typec/class.h b/drivers/usb/typec/class.h
> > index db2fe96c48ff..c53a04b9dc75 100644
> > --- a/drivers/usb/typec/class.h
> > +++ b/drivers/usb/typec/class.h
> > @@ -80,6 +80,8 @@ struct typec_port {
> >        */
> >       struct device                   *usb2_dev;
> >       struct device                   *usb3_dev;
> > +
> > +     bool                            mode_control;
>
> Shouldn't this go up higher in this structure, to avoid the hole you
> created, and to take advantage of the existing hole?  Perhaps after
> orientation?
>

I will replace the variable.

Thanks,
Andrei