Commit bed97b30 authored by Hans de Goede's avatar Hans de Goede Committed by Greg Kroah-Hartman
Browse files

usb: typec: ucsi: Hold con->lock for the entire duration of ucsi_register_port() 



Commit 081da132 ("usb: typec: ucsi: displayport: Fix a potential race
during registration") made the ucsi code hold con->lock in
ucsi_register_displayport(). But we really don't want any interactions
with the connector to run before the port-registration process is fully
complete.

This commit moves the taking of con->lock from ucsi_register_displayport()
into ucsi_register_port() to achieve this.

Cc: stable@vger.kernel.org
Fixes: 081da132 ("usb: typec: ucsi: displayport: Fix a potential race during registration")
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Acked-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200809141904.4317-5-hdegoede@redhat.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 25794e30

drivers/usb/typec/ucsi/displayport.c

+1 −8
Original line number Diff line number Diff line
@@ -288,8 +288,6 @@ struct typec_altmode *ucsi_register_displayport(struct ucsi_connector *con, 
	struct typec_altmode *alt;

	struct ucsi_dp *dp;



	mutex_lock(&con->lock);



	/* We can't rely on the firmware with the capabilities. */

	desc->vdo |= DP_CAP_DP_SIGNALING | DP_CAP_RECEPTACLE;
@@ -298,15 +296,12 @@ struct typec_altmode *ucsi_register_displayport(struct ucsi_connector *con, 
	desc->vdo |= all_assignments << 16;



	alt = typec_port_register_altmode(con->port, desc);

	if (IS_ERR(alt)) {

		mutex_unlock(&con->lock);

	if (IS_ERR(alt))

		return alt;

	}



	dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);

	if (!dp) {

		typec_unregister_altmode(alt);

		mutex_unlock(&con->lock);

		return ERR_PTR(-ENOMEM);

	}
@@ -319,7 +314,5 @@ struct typec_altmode *ucsi_register_displayport(struct ucsi_connector *con, 
	alt->ops = &ucsi_displayport_ops;

	typec_altmode_set_drvdata(alt, dp);



	mutex_unlock(&con->lock);



	return alt;

}

drivers/usb/typec/ucsi/ucsi.c

+22 −9
Original line number Diff line number Diff line
@@ -898,12 +898,15 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) 
	con->num = index + 1;

	con->ucsi = ucsi;



	/* Delay other interactions with the con until registration is complete */

	mutex_lock(&con->lock);



	/* Get connector capability */

	command = UCSI_GET_CONNECTOR_CAPABILITY;

	command |= UCSI_CONNECTOR_NUMBER(con->num);

	ret = ucsi_send_command(ucsi, command, &con->cap, sizeof(con->cap));

	if (ret < 0)

		return ret;

		goto out;



	if (con->cap.op_mode & UCSI_CONCAP_OPMODE_DRP)

		cap->data = TYPEC_PORT_DRD;
@@ -935,26 +938,32 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) 


	ret = ucsi_register_port_psy(con);

	if (ret)

		return ret;

		goto out;



	/* Register the connector */

	con->port = typec_register_port(ucsi->dev, cap);

	if (IS_ERR(con->port))

		return PTR_ERR(con->port);

	if (IS_ERR(con->port)) {

		ret = PTR_ERR(con->port);

		goto out;

	}



	/* Alternate modes */

	ret = ucsi_register_altmodes(con, UCSI_RECIPIENT_CON);

	if (ret)

	if (ret) {

		dev_err(ucsi->dev, "con%d: failed to register alt modes\n",

			con->num);

		goto out;

	}



	/* Get the status */

	command = UCSI_GET_CONNECTOR_STATUS | UCSI_CONNECTOR_NUMBER(con->num);

	ret = ucsi_send_command(ucsi, command, &con->status, sizeof(con->status));

	if (ret < 0) {

		dev_err(ucsi->dev, "con%d: failed to get status\n", con->num);

		return 0;

		ret = 0;

		goto out;

	}

	ret = 0; /* ucsi_send_command() returns length on success */



	switch (UCSI_CONSTAT_PARTNER_TYPE(con->status.flags)) {

	case UCSI_CONSTAT_PARTNER_TYPE_UFP:
@@ -979,17 +988,21 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) 


	if (con->partner) {

		ret = ucsi_register_altmodes(con, UCSI_RECIPIENT_SOP);

		if (ret)

		if (ret) {

			dev_err(ucsi->dev,

				"con%d: failed to register alternate modes\n",

				con->num);

		else

			ret = 0;

		} else {

			ucsi_altmode_update_active(con);

		}

	}



	trace_ucsi_register_port(con->num, &con->status);



	return 0;

out:

	mutex_unlock(&con->lock);

	return ret;

}



/**

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