linux-kernel - Re: [PATCH 3/3] platform/chrome: typec: Register port partner

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Message-ID: <20200409224058.GC15090@google.com>
Date:   Thu, 9 Apr 2020 15:40:58 -0700
From:   Prashant Malani <pmalani@...omium.org>
To:     Enric Balletbo i Serra <enric.balletbo@...labora.com>
Cc:     linux-kernel@...r.kernel.org, heikki.krogerus@...ux.intel.com,
        Jon Flatley <jflat@...omium.org>,
        Benson Leung <bleung@...omium.org>,
        Guenter Roeck <groeck@...omium.org>
Subject: Re: [PATCH 3/3] platform/chrome: typec: Register port partner

Hi Enric,

Thanks as always. Response inline:

On Thu, Apr 09, 2020 at 11:40:39PM +0200, Enric Balletbo i Serra wrote:
> Hi Prashant,
> 
> Thank you for your patch.
> 
> On 7/4/20 3:09, Prashant Malani wrote:
> > Register (and unregister) the port partner when a connect (and
> > disconnect) is detected.
> > 
> > Co-developed-by: Jon Flatley <jflat@...omium.org>
> > Signed-off-by: Prashant Malani <pmalani@...omium.org>
> > ---
> >  drivers/platform/chrome/cros_ec_typec.c | 47 +++++++++++++++++++++++++
> >  1 file changed, 47 insertions(+)
> > 
> > diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> > index 1955e1dfebc6d..e7d4d6ccccca6 100644
> > --- a/drivers/platform/chrome/cros_ec_typec.c
> > +++ b/drivers/platform/chrome/cros_ec_typec.c
> > @@ -22,6 +22,9 @@ struct cros_typec_port {
> >  	struct typec_port *port;
> >  	/* Initial capabilities for the port. */
> >  	struct typec_capability caps;
> > +	struct typec_partner *partner;
> > +	/* Port partner PD identity info. */
> > +	struct usb_pd_identity p_identity;
> >  };
> >  
> >  /* Platform-specific data for the Chrome OS EC Type C controller. */
> > @@ -191,6 +194,29 @@ static int cros_typec_ec_command(struct cros_typec_data *typec,
> >  	return ret;
> >  }
> >  
> > +static int cros_typec_add_partner(struct cros_typec_data *typec, int port_num,
> > +				  bool pd_en)
> > +{
> > +	struct cros_typec_port *port = typec->ports[port_num];
> > +	struct typec_partner_desc p_desc = {
> > +		.usb_pd = pd_en,
> > +	};
> > +
> > +	/*
> > +	 * Fill an initial PD identity, which will then be updated with info
> > +	 * from the EC.
> > +	 */
> > +	p_desc.identity = &port->p_identity;
> > +
> > +	port->partner = typec_register_partner(port->port, &p_desc);
> > +	if (IS_ERR_OR_NULL(port->partner)) {
> > +		port->partner = NULL;
> > +		return PTR_ERR(port->partner);
> 
> This is always returning PTR_ERR(NULL) that yields 0, that's not what you want.
> A static checker warning will be triggered.
> 
Got it. I will use a "ret" variable.
> 
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  static void cros_typec_set_port_params_v0(struct cros_typec_data *typec,
> >  		int port_num, struct ec_response_usb_pd_control *resp)
> >  {
> > @@ -213,6 +239,8 @@ static void cros_typec_set_port_params_v1(struct cros_typec_data *typec,
> >  {
> >  	struct typec_port *port = typec->ports[port_num]->port;
> >  	enum typec_orientation polarity;
> > +	bool pd_en;
> > +	int ret;
> >  
> >  	if (!(resp->enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
> >  		polarity = TYPEC_ORIENTATION_NONE;
> > @@ -227,6 +255,25 @@ static void cros_typec_set_port_params_v1(struct cros_typec_data *typec,
> >  			TYPEC_SOURCE : TYPEC_SINK);
> >  	typec_set_vconn_role(port, resp->role & PD_CTRL_RESP_ROLE_VCONN ?
> >  			TYPEC_SOURCE : TYPEC_SINK);
> > +
> > +	/* Register/remove partners when a connect/disconnect occurs. */
> > +	if (resp->enabled & PD_CTRL_RESP_ENABLED_CONNECTED) {
> > +		if (typec->ports[port_num]->partner)
> > +			return;
> > +
> > +		pd_en = resp->enabled & PD_CTRL_RESP_ENABLED_PD_CAPABLE;
> > +		ret = cros_typec_add_partner(typec, port_num, pd_en);
> > +		if (!ret)
> > +			dev_warn(typec->dev,
> > +				 "Failed to register partner on port: %d\n",
> > +				 port_num);
> > +	} else {
> > +		if (!typec->ports[port_num]->partner)
> > +			return;
> > +
> > +		typec_unregister_partner(typec->ports[port_num]->partner);
> > +		typec->ports[port_num]->partner = NULL;
> > +	}
> >  }
> >  
> >  static int cros_typec_port_update(struct cros_typec_data *typec, int port_num)
> >