Merge tag 'v4.4-rc6'
[firefly-linux-kernel-4.4.55.git] / drivers / usb / core / port.c
index 84c052f1aaec67b2bc2b53215a4e5feebfbe9c79..5487fe308f01b7be30bcecebc12726a295f9daa9 100644 (file)
 
 #include "hub.h"
 
+static int usb_port_block_power_off;
+
 static const struct attribute_group *port_dev_group[];
 
-static ssize_t show_port_connect_type(struct device *dev,
-       struct device_attribute *attr, char *buf)
+static ssize_t connect_type_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
 {
        struct usb_port *port_dev = to_usb_port(dev);
        char *result;
@@ -46,8 +48,7 @@ static ssize_t show_port_connect_type(struct device *dev,
 
        return sprintf(buf, "%s\n", result);
 }
-static DEVICE_ATTR(connect_type, S_IRUGO, show_port_connect_type,
-               NULL);
+static DEVICE_ATTR_RO(connect_type);
 
 static struct attribute *port_dev_attrs[] = {
        &dev_attr_connect_type.attr,
@@ -67,43 +68,64 @@ static void usb_port_device_release(struct device *dev)
 {
        struct usb_port *port_dev = to_usb_port(dev);
 
+       kfree(port_dev->req);
        kfree(port_dev);
 }
 
-#ifdef CONFIG_PM_RUNTIME
+#ifdef CONFIG_PM
 static int usb_port_runtime_resume(struct device *dev)
 {
        struct usb_port *port_dev = to_usb_port(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);
 
-       retval = usb_hub_set_port_power(hdev, port1, true);
-       if (port_dev->child && !retval) {
+       usb_autopm_get_interface(intf);
+       retval = usb_hub_set_port_power(hdev, hub, port1, true);
+       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
-                * disconnected while the port was powered off, so ignore the
-                * return status.
+                * Our preference is to simply wait for the port to reconnect,
+                * as that is the lowest latency method to restart the port.
+                * However, there are cases where toggling port power results in
+                * the host port and the device port getting out of sync causing
+                * a link training live lock.  Upon timeout, flag the port as
+                * needing warm reset recovery (to be performed later by
+                * usb_port_resume() as requested via usb_wakeup_notification())
                 */
-               retval = hub_port_debounce_be_connected(hub, port1);
-               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;
+               if (hub_port_debounce_be_connected(hub, port1) < 0) {
+                       dev_dbg(&port_dev->dev, "reconnect timeout\n");
+                       if (hub_is_superspeed(hdev))
+                               set_bit(port1, hub->warm_reset_bits);
+               }
+
+               /* 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;
 }
 
@@ -113,29 +135,43 @@ 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;
 
+       if (usb_port_block_power_off)
+               return -EBUSY;
+
        usb_autopm_get_interface(intf);
-       set_bit(port1, hub->busy_bits);
-       retval = usb_hub_set_port_power(hdev, port1, false);
+       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
 
 static const struct dev_pm_ops usb_port_pm_ops = {
-#ifdef CONFIG_PM_RUNTIME
+#ifdef CONFIG_PM
        .runtime_suspend =      usb_port_runtime_suspend,
        .runtime_resume =       usb_port_runtime_resume,
 #endif
@@ -147,51 +183,305 @@ 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;
+               char *method;
+
+               if (left->location && left->location == right->location)
+                       method = "location";
+               else
+                       method = "default";
+
+               pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
+                       dev_name(&left->dev), dev_name(&right->dev), method,
+                       dev_name(&left->dev),
+                       lpeer ? dev_name(&lpeer->dev) : "none",
+                       dev_name(&right->dev),
+                       rpeer ? dev_name(&rpeer->dev) : "none");
+               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_dbg(&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");
+               usb_port_block_power_off = 1;
+       }
+}
+
+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);
-       if (!port_dev) {
-               retval = -ENOMEM;
-               goto exit;
+       if (!port_dev)
+               return -ENOMEM;
+
+       port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
+       if (!port_dev->req) {
+               kfree(port_dev);
+               return -ENOMEM;
        }
 
        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;
+       if (retval) {
+               put_device(&port_dev->dev);
+               return retval;
+       }
+
+       /* Set default policy of port-poweroff disabled. */
+       retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
+                       DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
+       if (retval < 0) {
+               device_unregister(&port_dev->dev);
+               return retval;
+       }
+
+       find_and_link_peer(hub, port1);
 
+       /*
+        * Enable runtime pm and hold a refernce that hub_configure()
+        * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
+        * and the hub has been fully registered (hdev->maxchild set).
+        */
        pm_runtime_set_active(&port_dev->dev);
+       pm_runtime_get_noresume(&port_dev->dev);
+       pm_runtime_enable(&port_dev->dev);
+       device_enable_async_suspend(&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.
+       /*
+        * Keep hidden the ability to enable port-poweroff if the hub
+        * does not support power switching.
         */
-       if (!dev_pm_qos_expose_flags(&port_dev->dev,
-                       PM_QOS_FLAG_NO_POWER_OFF))
-               pm_runtime_enable(&port_dev->dev);
+       if (!hub_is_port_power_switchable(hub))
+               return 0;
+
+       /* Attempt to let userspace take over the policy. */
+       retval = dev_pm_qos_expose_flags(&port_dev->dev,
+                       PM_QOS_FLAG_NO_POWER_OFF);
+       if (retval < 0) {
+               dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
+               return 0;
+       }
 
-       device_enable_async_suspend(&port_dev->dev);
+       /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
+       retval = dev_pm_qos_remove_request(port_dev->req);
+       if (retval >= 0) {
+               kfree(port_dev->req);
+               port_dev->req = NULL;
+       }
        return 0;
-
-error_register:
-       put_device(&port_dev->dev);
-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);
+}