Assume that the peer of a superspeed port is the port with the same id
on the shared_hcd root hub. This identification scheme is required of
external hubs by the USB3 spec [1]. However, for root hubs, tier mismatch
may be in effect [2]. Tier mismatch can only be enumerated via platform
firmware. For now, simply perform the nominal association.
[1]: usb 3.1 section 10.3.3
[2]: xhci 1.1 appendix D
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/core/hub.h | 2 +
drivers/usb/core/port.c | 98 ++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 94 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index baf5b48b79f7..d51feb68165b 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -81,6 +81,7 @@ struct usb_hub {
* @child: usb device attached to the port
* @dev: generic device interface
* @port_owner: port's owner
+ * @peer: related usb2 and usb3 ports (share the same connector)
* @connect_type: port's connect type
* @portnum: port index num based one
* @power_is_on: port's power state
@@ -90,6 +91,7 @@ struct usb_port {
struct usb_device *child;
struct device dev;
struct dev_state *port_owner;
+ struct usb_port *peer;
enum usb_port_connect_type connect_type;
u8 portnum;
unsigned power_is_on:1;
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 9ae8a499b70f..d57fb01bbc1c 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -21,6 +21,7 @@
#include "hub.h"
+static DEFINE_MUTEX(peer_lock);
static const struct attribute_group *port_dev_group[];
static ssize_t connect_type_show(struct device *dev,
@@ -146,9 +147,83 @@ struct device_type usb_port_device_type = {
.pm = &usb_port_pm_ops,
};
+/*
+ * Set the default peer port for root hubs. Platform firmware will have
+ * already set the peer if tier-mismatch is present. Assumes the
+ * primary_hcd is registered first
+ */
+static struct usb_port *find_default_peer(struct usb_hub *hub, int port1)
+{
+ struct usb_device *hdev = hub->hdev;
+ struct usb_port *peer = NULL;
+
+ if (!hdev->parent) {
+ struct usb_hub *peer_hub;
+ struct usb_device *peer_hdev;
+ struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
+ struct usb_hcd *peer_hcd = hcd->primary_hcd;
+
+ if (!peer_hcd || hcd == peer_hcd)
+ return NULL;
+
+ peer_hdev = peer_hcd->self.root_hub;
+ peer_hub = usb_hub_to_struct_hub(peer_hdev);
+ if (peer_hub && port1 <= peer_hdev->maxchild)
+ peer = peer_hub->ports[port1 - 1];
+ }
+
+ return peer;
+}
+
+static void link_peers(struct usb_port *left, struct usb_port *right)
+{
+ struct device *rdev;
+ struct device *ldev;
+
+ if (left->peer) {
+ right = left->peer;
+ ldev = left->dev.parent->parent;
+ rdev = right->dev.parent->parent;
+
+ WARN_ONCE(1, "%s port%d already peered with %s %d\n",
+ dev_name(ldev), left->portnum, dev_name(rdev),
+ right->portnum);
+ return;
+ } else if (right->peer) {
+ left = right->peer;
+ ldev = left->dev.parent->parent;
+ rdev = right->dev.parent->parent;
+
+ WARN_ONCE(1, "%s port%d already peered with %s %d\n",
+ dev_name(rdev), right->portnum, dev_name(ldev),
+ left->portnum);
+ return;
+ }
+
+ get_device(&right->dev);
+ left->peer = right;
+ get_device(&left->dev);
+ right->peer = left;
+}
+
+static void unlink_peers(struct usb_port *left, struct usb_port *right)
+{
+ struct device *rdev = right->dev.parent->parent;
+ struct device *ldev = left->dev.parent->parent;
+
+ WARN_ONCE(right->peer != left || left->peer != right,
+ "%s port%d and %s port%d are not peers?\n",
+ dev_name(ldev), left->portnum, dev_name(rdev), right->portnum);
+
+ put_device(&left->dev);
+ right->peer = NULL;
+ put_device(&right->dev);
+ left->peer = NULL;
+}
+
int usb_hub_create_port_device(struct usb_hub *hub, int port1)
{
- struct usb_port *port_dev = NULL;
+ struct usb_port *port_dev, *peer;
int retval;
port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
@@ -164,11 +239,16 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
port_dev->dev.groups = port_dev_group;
port_dev->dev.type = &usb_port_device_type;
dev_set_name(&port_dev->dev, "port%d", port1);
-
retval = device_register(&port_dev->dev);
if (retval)
goto error_register;
+ mutex_lock(&peer_lock);
+ peer = find_default_peer(hub, port1);
+ if (peer)
+ link_peers(port_dev, peer);
+ mutex_unlock(&peer_lock);
+
pm_runtime_set_active(&port_dev->dev);
/* It would be dangerous if user space couldn't prevent usb
@@ -190,9 +270,15 @@ 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 = port_dev->peer;
+ mutex_lock(&peer_lock);
+ if (peer)
+ unlink_peers(port_dev, peer);
+ mutex_unlock(&peer_lock);
+
+ device_unregister(&port_dev->dev);
+}
--
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