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Date: Tue, 24 May 2016 12:28:26 -0700
From: Guenter Roeck <linux@roeck-us.net>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
        Oliver Neukum <oneukum@suse.com>,
        Rajaram R <rajaram.officemail@gmail.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [RFC PATCHv2] usb: USB Type-C Connector Class
Message-ID: <20160524192826.GA28453@roeck-us.net>
References: <1463661894-22820-1-git-send-email-heikki.krogerus@linux.intel.com>
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On Thu, May 19, 2016 at 03:44:54PM +0300, Heikki Krogerus wrote:
> The purpose of this class is to provide unified interface for user
> space to get the status and basic information about USB Type-C
> Connectors in the system, control data role swapping, and when USB PD
> is available, also power role swapping and Alternate Modes.
> 
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

[ ... ]

> +
> +static void typec_remove_partner(struct typec_port *port)
> +{
> +	sysfs_remove_link(&port->dev.kobj, "partner");
> +	typec_unregister_altmodes(port->partner->alt_modes);

This only unregisters alternate modes registered through typec_add_partner(),
but not alternate modes registered separately. Or is the calling code expected
to set port->partner->alt_modes when calling typec_register_altmodes()
directly ?

[ ... ]

> +
> +void typec_unregister_altmodes(struct typec_altmode *alt_modes)
> +{
> +	struct typec_altmode *alt;
> +
This will crash if alt_modes is NULL, which will happen if 
partner->alt_modes is NULL at connection time. Semantically
this is different to typec_register_altmodes(), which does
have a NULL check.

Guenter