linux-kernel - Re: [PATCH v3 3/7] usb: typec: Check port is active before enter mode on probe

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Message-ID: <Zy4CNtSDjbPTcCcI@kuha.fi.intel.com>
Date: Fri, 8 Nov 2024 14:21:10 +0200
From: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
Cc: tzungbi@...nel.org, linux-usb@...r.kernel.org,
	chrome-platform@...ts.linux.dev, jthies@...gle.com,
	akuchynski@...gle.com, pmalani@...omium.org,
	dmitry.baryshkov@...aro.org,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 3/7] usb: typec: Check port is active before enter
 mode on probe

On Thu, Nov 07, 2024 at 11:29:56AM -0800, Abhishek Pandit-Subedi wrote:
> Enforce the same requirement as when we attempt to activate altmode via
> sysfs (do not enter partner mode if port mode is not active). In order
> to set a default value for this field, also introduce the inactive field
> in struct typec_altmode_desc.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>

Reviewed-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>

> ---
> 
> Changes in v3:
> - Use port.active instead of introducing auto-enter field
> - Introduce inactive field to typec_altmode_desc to set default value
>   for active.
> - Always make port 'active' field writable
> 
>  drivers/usb/typec/altmodes/displayport.c | 7 +++++--
>  drivers/usb/typec/altmodes/thunderbolt.c | 6 +++++-
>  drivers/usb/typec/class.c                | 5 +++--
>  include/linux/usb/typec.h                | 2 ++
>  4 files changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index 3245e03d59e6..f4116e96f6a1 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -767,8 +767,11 @@ int dp_altmode_probe(struct typec_altmode *alt)
>  	if (plug)
>  		typec_altmode_set_drvdata(plug, dp);
>  
> -	dp->state = plug ? DP_STATE_ENTER_PRIME : DP_STATE_ENTER;
> -	schedule_work(&dp->work);
> +	/* Only attempt to enter altmode if port is active. */
> +	if (port->active) {
> +		dp->state = plug ? DP_STATE_ENTER_PRIME : DP_STATE_ENTER;
> +		schedule_work(&dp->work);
> +	}
>  
>  	return 0;
>  }
> diff --git a/drivers/usb/typec/altmodes/thunderbolt.c b/drivers/usb/typec/altmodes/thunderbolt.c
> index a945b9d35a1d..45567abc3bb8 100644
> --- a/drivers/usb/typec/altmodes/thunderbolt.c
> +++ b/drivers/usb/typec/altmodes/thunderbolt.c
> @@ -212,6 +212,7 @@ static const struct typec_altmode_ops tbt_altmode_ops = {
>  
>  static int tbt_altmode_probe(struct typec_altmode *alt)
>  {
> +	const struct typec_altmode *port = typec_altmode_get_partner(alt);
>  	struct tbt_altmode *tbt;
>  
>  	tbt = devm_kzalloc(&alt->dev, sizeof(*tbt), GFP_KERNEL);
> @@ -226,7 +227,10 @@ static int tbt_altmode_probe(struct typec_altmode *alt)
>  	typec_altmode_set_drvdata(alt, tbt);
>  	typec_altmode_set_ops(alt, &tbt_altmode_ops);
>  
> -	if (tbt_ready(alt)) {
> +	/* Only attempt to enter altmode if port is active and cable/plug
> +	 * information is ready.
> +	 */
> +	if (port->active && tbt_ready(alt)) {
>  		if (tbt->plug[TYPEC_PLUG_SOP_PP])
>  			tbt->state = TBT_STATE_SOP_PP_ENTER;
>  		else if (tbt->plug[TYPEC_PLUG_SOP_P])
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index febe453b96be..b5e67a57762c 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -458,7 +458,8 @@ static umode_t typec_altmode_attr_is_visible(struct kobject *kobj,
>  	struct typec_altmode *adev = to_typec_altmode(kobj_to_dev(kobj));
>  
>  	if (attr == &dev_attr_active.attr)
> -		if (!adev->ops || !adev->ops->activate)
> +		if (!is_typec_port(adev->dev.parent) &&
> +		    (!adev->ops || !adev->ops->activate))
>  			return 0444;
>  
>  	return attr->mode;
> @@ -563,7 +564,7 @@ typec_register_altmode(struct device *parent,
>  
>  	if (is_port) {
>  		alt->attrs[3] = &dev_attr_supported_roles.attr;
> -		alt->adev.active = true; /* Enabled by default */
> +		alt->adev.active = !desc->inactive; /* Enabled by default */
>  	}
>  
>  	sprintf(alt->group_name, "mode%d", desc->mode);
> diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h
> index d616b8807000..56c01771c190 100644
> --- a/include/linux/usb/typec.h
> +++ b/include/linux/usb/typec.h
> @@ -140,6 +140,7 @@ int typec_cable_set_identity(struct typec_cable *cable);
>   * @mode: Index of the Mode
>   * @vdo: VDO returned by Discover Modes USB PD command
>   * @roles: Only for ports. DRP if the mode is available in both roles
> + * @inactive: Only for ports. Make this port inactive (default is active).
>   *
>   * Description of an Alternate Mode which a connector, cable plug or partner
>   * supports.
> @@ -150,6 +151,7 @@ struct typec_altmode_desc {
>  	u32			vdo;
>  	/* Only used with ports */
>  	enum typec_port_data	roles;
> +	bool			inactive : 1;
>  };
>  
>  void typec_partner_set_pd_revision(struct typec_partner *partner, u16 pd_revision);
> -- 
> 2.47.0.277.g8800431eea-goog

-- 
heikki