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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.c289
1 files changed, 268 insertions, 21 deletions
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 51542f852393..62036faf56c0 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -76,17 +76,29 @@ static int usb_port_runtime_resume(struct device *dev)
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_interface *intf = to_usb_interface(dev->parent);
struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+ struct usb_device *udev = port_dev->child;
+ struct usb_port *peer = port_dev->peer;
int port1 = port_dev->portnum;
int retval;
if (!hub)
return -EINVAL;
+ if (hub->in_reset) {
+ set_bit(port1, hub->power_bits);
+ return 0;
+ }
- usb_autopm_get_interface(intf);
- set_bit(port1, hub->busy_bits);
+ /*
+ * Power on our usb3 peer before this usb2 port to prevent a usb3
+ * device from degrading to its usb2 connection
+ */
+ if (!port_dev->is_superspeed && peer)
+ pm_runtime_get_sync(&peer->dev);
+ usb_autopm_get_interface(intf);
retval = usb_hub_set_port_power(hdev, hub, port1, true);
- if (port_dev->child && !retval) {
+ msleep(hub_power_on_good_delay(hub));
+ if (udev && !retval) {
/*
* Attempt to wait for usb hub port to be reconnected in order
* to make the resume procedure successful. The device may have
@@ -97,12 +109,17 @@ static int usb_port_runtime_resume(struct device *dev)
if (retval < 0)
dev_dbg(&port_dev->dev, "can't get reconnection after setting port power on, status %d\n",
retval);
- usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
retval = 0;
+
+ /* Force the child awake to revalidate after the power loss. */
+ if (!test_and_set_bit(port1, hub->child_usage_bits)) {
+ pm_runtime_get_noresume(&port_dev->dev);
+ pm_request_resume(&udev->dev);
+ }
}
- clear_bit(port1, hub->busy_bits);
usb_autopm_put_interface(intf);
+
return retval;
}
@@ -112,23 +129,34 @@ static int usb_port_runtime_suspend(struct device *dev)
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_interface *intf = to_usb_interface(dev->parent);
struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
+ struct usb_port *peer = port_dev->peer;
int port1 = port_dev->portnum;
int retval;
if (!hub)
return -EINVAL;
+ if (hub->in_reset)
+ return -EBUSY;
if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
== PM_QOS_FLAGS_ALL)
return -EAGAIN;
usb_autopm_get_interface(intf);
- set_bit(port1, hub->busy_bits);
retval = usb_hub_set_port_power(hdev, hub, port1, false);
usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
- usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
- clear_bit(port1, hub->busy_bits);
+ if (!port_dev->is_superspeed)
+ usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
usb_autopm_put_interface(intf);
+
+ /*
+ * Our peer usb3 port may now be able to suspend, so
+ * asynchronously queue a suspend request to observe that this
+ * usb2 port is now off.
+ */
+ if (!port_dev->is_superspeed && peer)
+ pm_runtime_put(&peer->dev);
+
return retval;
}
#endif
@@ -146,9 +174,215 @@ struct device_type usb_port_device_type = {
.pm = &usb_port_pm_ops,
};
+static struct device_driver usb_port_driver = {
+ .name = "usb",
+ .owner = THIS_MODULE,
+};
+
+static int link_peers(struct usb_port *left, struct usb_port *right)
+{
+ struct usb_port *ss_port, *hs_port;
+ int rc;
+
+ if (left->peer == right && right->peer == left)
+ return 0;
+
+ if (left->peer || right->peer) {
+ struct usb_port *lpeer = left->peer;
+ struct usb_port *rpeer = right->peer;
+
+ WARN(1, "failed to peer %s and %s (%s -> %p) (%s -> %p)\n",
+ dev_name(&left->dev), dev_name(&right->dev),
+ dev_name(&left->dev), lpeer,
+ dev_name(&right->dev), rpeer);
+ return -EBUSY;
+ }
+
+ rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
+ if (rc)
+ return rc;
+ rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
+ if (rc) {
+ sysfs_remove_link(&left->dev.kobj, "peer");
+ return rc;
+ }
+
+ /*
+ * We need to wake the HiSpeed port to make sure we don't race
+ * setting ->peer with usb_port_runtime_suspend(). Otherwise we
+ * may miss a suspend event for the SuperSpeed port.
+ */
+ if (left->is_superspeed) {
+ ss_port = left;
+ WARN_ON(right->is_superspeed);
+ hs_port = right;
+ } else {
+ ss_port = right;
+ WARN_ON(!right->is_superspeed);
+ hs_port = left;
+ }
+ pm_runtime_get_sync(&hs_port->dev);
+
+ left->peer = right;
+ right->peer = left;
+
+ /*
+ * The SuperSpeed reference is dropped when the HiSpeed port in
+ * this relationship suspends, i.e. when it is safe to allow a
+ * SuperSpeed connection to drop since there is no risk of a
+ * device degrading to its powered-off HiSpeed connection.
+ *
+ * Also, drop the HiSpeed ref taken above.
+ */
+ pm_runtime_get_sync(&ss_port->dev);
+ pm_runtime_put(&hs_port->dev);
+
+ return 0;
+}
+
+static void link_peers_report(struct usb_port *left, struct usb_port *right)
+{
+ int rc;
+
+ rc = link_peers(left, right);
+ if (rc == 0) {
+ dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
+ } else {
+ dev_warn(&left->dev, "failed to peer to %s (%d)\n",
+ dev_name(&right->dev), rc);
+ pr_warn_once("usb: port power management may be unreliable\n");
+ }
+}
+
+static void unlink_peers(struct usb_port *left, struct usb_port *right)
+{
+ struct usb_port *ss_port, *hs_port;
+
+ WARN(right->peer != left || left->peer != right,
+ "%s and %s are not peers?\n",
+ dev_name(&left->dev), dev_name(&right->dev));
+
+ /*
+ * We wake the HiSpeed port to make sure we don't race its
+ * usb_port_runtime_resume() event which takes a SuperSpeed ref
+ * when ->peer is !NULL.
+ */
+ if (left->is_superspeed) {
+ ss_port = left;
+ hs_port = right;
+ } else {
+ ss_port = right;
+ hs_port = left;
+ }
+
+ pm_runtime_get_sync(&hs_port->dev);
+
+ sysfs_remove_link(&left->dev.kobj, "peer");
+ right->peer = NULL;
+ sysfs_remove_link(&right->dev.kobj, "peer");
+ left->peer = NULL;
+
+ /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
+ pm_runtime_put(&ss_port->dev);
+
+ /* Drop the ref taken above */
+ pm_runtime_put(&hs_port->dev);
+}
+
+/*
+ * For each usb hub device in the system check to see if it is in the
+ * peer domain of the given port_dev, and if it is check to see if it
+ * has a port that matches the given port by location
+ */
+static int match_location(struct usb_device *peer_hdev, void *p)
+{
+ int port1;
+ struct usb_hcd *hcd, *peer_hcd;
+ struct usb_port *port_dev = p, *peer;
+ 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)
+ return 0;
+
+ hcd = bus_to_hcd(hdev->bus);
+ peer_hcd = bus_to_hcd(peer_hdev->bus);
+ /* peer_hcd is provisional until we verify it against the known peer */
+ if (peer_hcd != hcd->shared_hcd)
+ return 0;
+
+ for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
+ peer = peer_hub->ports[port1 - 1];
+ if (peer && peer->location == port_dev->location) {
+ link_peers_report(port_dev, peer);
+ return 1; /* done */
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Find the peer port either via explicit platform firmware "location"
+ * data, the peer hcd for root hubs, or the upstream peer relationship
+ * for all other hubs.
+ */
+static void find_and_link_peer(struct usb_hub *hub, int port1)
+{
+ struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
+ struct usb_device *hdev = hub->hdev;
+ struct usb_device *peer_hdev;
+ struct usb_hub *peer_hub;
+
+ /*
+ * If location data is available then we can only peer this port
+ * by a location match, not the default peer (lest we create a
+ * situation where we need to go back and undo a default peering
+ * when the port is later peered by location data)
+ */
+ if (port_dev->location) {
+ /* we link the peer in match_location() if found */
+ usb_for_each_dev(port_dev, match_location);
+ return;
+ } else if (!hdev->parent) {
+ struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
+ struct usb_hcd *peer_hcd = hcd->shared_hcd;
+
+ if (!peer_hcd)
+ return;
+
+ peer_hdev = peer_hcd->self.root_hub;
+ } else {
+ struct usb_port *upstream;
+ struct usb_device *parent = hdev->parent;
+ struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
+
+ if (!parent_hub)
+ return;
+
+ upstream = parent_hub->ports[hdev->portnum - 1];
+ if (!upstream || !upstream->peer)
+ return;
+
+ peer_hdev = upstream->peer->child;
+ }
+
+ peer_hub = usb_hub_to_struct_hub(peer_hdev);
+ if (!peer_hub || port1 > peer_hdev->maxchild)
+ return;
+
+ /*
+ * we found a valid default peer, last check is to make sure it
+ * does not have location data
+ */
+ peer = peer_hub->ports[port1 - 1];
+ if (peer && peer->location == 0)
+ link_peers_report(port_dev, peer);
+}
+
int usb_hub_create_port_device(struct usb_hub *hub, int port1)
{
- struct usb_port *port_dev = NULL;
+ struct usb_port *port_dev;
int retval;
port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
@@ -159,24 +393,33 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
hub->ports[port1 - 1] = port_dev;
port_dev->portnum = port1;
- port_dev->power_is_on = true;
+ set_bit(port1, hub->power_bits);
port_dev->dev.parent = hub->intfdev;
port_dev->dev.groups = port_dev_group;
port_dev->dev.type = &usb_port_device_type;
- dev_set_name(&port_dev->dev, "port%d", port1);
-
+ port_dev->dev.driver = &usb_port_driver;
+ if (hub_is_superspeed(hub->hdev))
+ port_dev->is_superspeed = 1;
+ dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
+ port1);
+ mutex_init(&port_dev->status_lock);
retval = device_register(&port_dev->dev);
if (retval)
goto error_register;
+ find_and_link_peer(hub, port1);
+
pm_runtime_set_active(&port_dev->dev);
- /* It would be dangerous if user space couldn't
- * prevent usb device from being powered off. So don't
- * enable port runtime pm if failed to expose port's pm qos.
+ /*
+ * Do not enable port runtime pm if the hub does not support
+ * power switching. Also, userspace must have final say of
+ * whether a port is permitted to power-off. Do not enable
+ * runtime pm if we fail to expose pm_qos_no_power_off.
*/
- if (!dev_pm_qos_expose_flags(&port_dev->dev,
- PM_QOS_FLAG_NO_POWER_OFF))
+ if (hub_is_port_power_switchable(hub)
+ && dev_pm_qos_expose_flags(&port_dev->dev,
+ PM_QOS_FLAG_NO_POWER_OFF) == 0)
pm_runtime_enable(&port_dev->dev);
device_enable_async_suspend(&port_dev->dev);
@@ -188,9 +431,13 @@ exit:
return retval;
}
-void usb_hub_remove_port_device(struct usb_hub *hub,
- int port1)
+void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
{
- device_unregister(&hub->ports[port1 - 1]->dev);
-}
+ struct usb_port *port_dev = hub->ports[port1 - 1];
+ struct usb_port *peer;
+ peer = port_dev->peer;
+ if (peer)
+ unlink_peers(port_dev, peer);
+ device_unregister(&port_dev->dev);
+}