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usb: typec: ucsi: displayport: Fix a potential race during registration

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Locking the connector in ucsi_register_displayport() to make
sure that nothing can access the displayport alternate mode
before the function has finished and the alternate mode is
actually ready.

Fixes: af8622f6a5 ("usb: typec: ucsi: Support for DisplayPort alt mode")
Cc: stable@vger.kernel.org
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200311130006.41288-3-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Heikki Krogerus 2020-03-11 16:00:06 +03:00 committed by Greg Kroah-Hartman
parent d16e7b62c5
commit 081da1325d
1 changed files with 8 additions and 1 deletions
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9
drivers/usb/typec/ucsi/displayport.c
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@ -288,6 +288,8 @@ 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;
@ -296,12 +298,15 @@ 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))
if (IS_ERR(alt)) {
mutex_unlock(&con->lock);
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);
}
@ -314,5 +319,7 @@ 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;
}