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

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Commit 081da1325d ("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: 081da1325d ("usb: typec: ucsi: displayport: Fix a potential race during registration")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200809141904.4317-5-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hans de Goede 2020-08-09 16:19:04 +02:00 committed by Greg Kroah-Hartman
parent 25794e3079
commit bed97b3096
2 changed files with 23 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/usb/typec/ucsi/displayport.c
View File

@ -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;
}

31
drivers/usb/typec/ucsi/ucsi.c
View File

@ -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;
}
/**