blob: fb6b698685e164ef035cf82a39d31c3c4d412355 [file] [log] [blame]
From bed97b30968ba354035a020989df0623e52b5536 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Sun, 9 Aug 2020 16:19:04 +0200
Subject: [PATCH] usb: typec: ucsi: Hold con->lock for the entire duration of
ucsi_register_port()
commit bed97b30968ba354035a020989df0623e52b5536 upstream.
Commit 081da1325d35 ("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: 081da1325d35 ("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>
diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c
index 048381c058a5..261131c9e37c 100644
--- a/drivers/usb/typec/ucsi/displayport.c
+++ b/drivers/usb/typec/ucsi/displayport.c
@@ -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;
}
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 8a35144211e5..e680fcfdee60 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -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;
}
/**
--
2.27.0