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From:   Badhri Jagan Sridharan <badhri@google.com>
Date:   Wed, 7 Apr 2021 13:13:24 -0700
Message-ID: <CAPTae5Lqv4E_w31gEWjqPB_-H9A=ed3NNhc=18psih_Vs1U4ug@mail.gmail.com>
Subject: Re: [PATCH v1 1/6] usb: typec: tcpm: Address incorrect values of tcpm
 psy for fixed supply
To:     Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Cc:     Guenter Roeck <linux@roeck-us.net>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        Kyle Tso <kyletso@google.com>
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Precedence: bulk

Hi Guenter and Adam,

Thanks for the reviews !
Fixed up the typo in V2.

Thanks,
Badhri

On Wed, Apr 7, 2021 at 9:04 AM Adam Thomson
<Adam.Thomson.Opensource@diasemi.com> wrote:
>
> On 06 April 2021 02:37, Badhri Jagan Sridharan wrote:
>
> > tcpm_pd_build_request overwrites current_limit and supply_voltage
> > even before port partner accepts the requests. This leaves stale
> > values in current_limit and supply_voltage that get exported by
> > "tcpm-source-psy-". Solving this problem by caching the request
> > values of current limit/supply voltage in req_current_limit
> > and req_supply_voltage. current_limit/supply_voltage gets updated
> > once the port partner accepts the request.
> >
> > Fixes: f2a8aa053c176 ("typec: tcpm: Represent source supply through
> > power_supply")
> > Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> > ---
>
> Looks sensible, typo aside:
>
> Reviewed-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
>
> >  drivers/usb/typec/tcpm/tcpm.c | 17 ++++++++++-------
> >  1 file changed, 10 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > index ca1fc77697fc..03eca5061132 100644
> > --- a/drivers/usb/typec/tcpm/tcpm.c
> > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > @@ -389,7 +389,10 @@ struct tcpm_port {
> >       unsigned int operating_snk_mw;
> >       bool update_sink_caps;
> >
> > -     /* Requested current / voltage */
> > +     /* Requested current / voltage to the port partner */
> > +     u32 req_current_limit;
> > +     u32 req_supply_voltage;
> > +     /* Acutal current / voltage limit of the local port */
> >       u32 current_limit;
> >       u32 supply_voltage;
> >
> > @@ -2435,8 +2438,8 @@ static void tcpm_pd_ctrl_request(struct tcpm_port
> > *port,
> >               case SNK_TRANSITION_SINK:
> >                       if (port->vbus_present) {
> >                               tcpm_set_current_limit(port,
> > -                                                    port->current_limit,
> > -                                                    port->supply_voltage);
> > +                                                    port->req_current_limit,
> > +                                                    port->req_supply_voltage);
> >                               port->explicit_contract = true;
> >                               tcpm_set_auto_vbus_discharge_threshold(port,
> >
> > TYPEC_PWR_MODE_PD,
> > @@ -2545,8 +2548,8 @@ static void tcpm_pd_ctrl_request(struct tcpm_port
> > *port,
> >                       break;
> >               case SNK_NEGOTIATE_PPS_CAPABILITIES:
> >                       port->pps_data.active = true;
> > -                     port->supply_voltage = port->pps_data.out_volt;
> > -                     port->current_limit = port->pps_data.op_curr;
> > +                     port->req_supply_voltage = port->pps_data.out_volt;
> > +                     port->req_current_limit = port->pps_data.op_curr;
> >                       tcpm_set_state(port, SNK_TRANSITION_SINK, 0);
> >                       break;
> >               case SOFT_RESET_SEND:
> > @@ -3195,8 +3198,8 @@ static int tcpm_pd_build_request(struct tcpm_port
> > *port, u32 *rdo)
> >                        flags & RDO_CAP_MISMATCH ? " [mismatch]" : "");
> >       }
> >
> > -     port->current_limit = ma;
> > -     port->supply_voltage = mv;
> > +     port->req_current_limit = ma;
> > +     port->req_supply_voltage = mv;
> >
> >       return 0;
> >  }
> > --
> > 2.31.0.208.g409f899ff0-goog
>