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path: root/drivers/usb/core/port.c
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Diffstat (limited to 'drivers/usb/core/port.c')
-rw-r--r--drivers/usb/core/port.c47
1 files changed, 40 insertions, 7 deletions
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index c628c1abc907..686c01af03e6 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -11,6 +11,7 @@
#include <linux/slab.h>
#include <linux/pm_qos.h>
#include <linux/component.h>
+#include <linux/usb/of.h>
#include "hub.h"
@@ -55,11 +56,22 @@ static ssize_t disable_show(struct device *dev,
u16 portstatus, unused;
bool disabled;
int rc;
+ struct kernfs_node *kn;
+ hub_get(hub);
rc = usb_autopm_get_interface(intf);
if (rc < 0)
- return rc;
+ goto out_hub_get;
+ /*
+ * Prevent deadlock if another process is concurrently
+ * trying to unregister hdev.
+ */
+ kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
+ if (!kn) {
+ rc = -ENODEV;
+ goto out_autopm;
+ }
usb_lock_device(hdev);
if (hub->disconnected) {
rc = -ENODEV;
@@ -69,9 +81,13 @@ static ssize_t disable_show(struct device *dev,
usb_hub_port_status(hub, port1, &portstatus, &unused);
disabled = !usb_port_is_power_on(hub, portstatus);
-out_hdev_lock:
+ out_hdev_lock:
usb_unlock_device(hdev);
+ sysfs_unbreak_active_protection(kn);
+ out_autopm:
usb_autopm_put_interface(intf);
+ out_hub_get:
+ hub_put(hub);
if (rc)
return rc;
@@ -89,15 +105,26 @@ static ssize_t disable_store(struct device *dev, struct device_attribute *attr,
int port1 = port_dev->portnum;
bool disabled;
int rc;
+ struct kernfs_node *kn;
rc = kstrtobool(buf, &disabled);
if (rc)
return rc;
+ hub_get(hub);
rc = usb_autopm_get_interface(intf);
if (rc < 0)
- return rc;
+ goto out_hub_get;
+ /*
+ * Prevent deadlock if another process is concurrently
+ * trying to unregister hdev.
+ */
+ kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
+ if (!kn) {
+ rc = -ENODEV;
+ goto out_autopm;
+ }
usb_lock_device(hdev);
if (hub->disconnected) {
rc = -ENODEV;
@@ -118,9 +145,13 @@ static ssize_t disable_store(struct device *dev, struct device_attribute *attr,
if (!rc)
rc = count;
-out_hdev_lock:
+ out_hdev_lock:
usb_unlock_device(hdev);
+ sysfs_unbreak_active_protection(kn);
+ out_autopm:
usb_autopm_put_interface(intf);
+ out_hub_get:
+ hub_put(hub);
return rc;
}
@@ -429,7 +460,7 @@ static const struct dev_pm_ops usb_port_pm_ops = {
#endif
};
-struct device_type usb_port_device_type = {
+const struct device_type usb_port_device_type = {
.name = "usb_port",
.release = usb_port_device_release,
.pm = &usb_port_pm_ops,
@@ -573,7 +604,7 @@ static int match_location(struct usb_device *peer_hdev, void *p)
struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
- if (!peer_hub)
+ if (!peer_hub || port_dev->connect_type == USB_PORT_NOT_USED)
return 0;
hcd = bus_to_hcd(hdev->bus);
@@ -584,7 +615,8 @@ static int match_location(struct usb_device *peer_hdev, void *p)
for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
peer = peer_hub->ports[port1 - 1];
- if (peer && peer->location == port_dev->location) {
+ if (peer && peer->connect_type != USB_PORT_NOT_USED &&
+ peer->location == port_dev->location) {
link_peers_report(port_dev, peer);
return 1; /* done */
}
@@ -708,6 +740,7 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
return -ENOMEM;
}
+ port_dev->connect_type = usb_of_get_connect_type(hdev, port1);
hub->ports[port1 - 1] = port_dev;
port_dev->portnum = port1;
set_bit(port1, hub->power_bits);