The usb topology after this change will have symlinks between usb3 ports
and their usb2 peers, for example:
usb2/2-1/2-1:1.0/port1/peer => ../../../../usb3/3-1/3-1:1.0/port1
usb2/2-1/2-1:1.0/port2/peer => ../../../../usb3/3-1/3-1:1.0/port2
usb2/2-1/2-1:1.0/port3/peer => ../../../../usb3/3-1/3-1:1.0/port3
usb2/2-1/2-1:1.0/port4/peer => ../../../../usb3/3-1/3-1:1.0/port4
usb2/2-0:1.0/port1/peer => ../../../usb3/3-0:1.0/port1
usb2/2-0:1.0/port2/peer => ../../../usb3/3-0:1.0/port2
usb2/2-0:1.0/port3/peer => ../../../usb3/3-0:1.0/port3
usb2/2-0:1.0/port4/peer => ../../../usb3/3-0:1.0/port4
usb3/3-1/3-1:1.0/port1/peer => ../../../../usb2/2-1/2-1:1.0/port1
usb3/3-1/3-1:1.0/port2/peer => ../../../../usb2/2-1/2-1:1.0/port2
usb3/3-1/3-1:1.0/port3/peer => ../../../../usb2/2-1/2-1:1.0/port3
usb3/3-1/3-1:1.0/port4/peer => ../../../../usb2/2-1/2-1:1.0/port4
usb3/3-0:1.0/port1/peer => ../../../usb2/2-0:1.0/port1
usb3/3-0:1.0/port2/peer => ../../../usb2/2-0:1.0/port2
usb3/3-0:1.0/port3/peer => ../../../usb2/2-0:1.0/port3
usb3/3-0:1.0/port4/peer => ../../../usb2/2-0:1.0/port4
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/core/port.c | 45 +++++++++++++++++++++++++++++++++++++++------
1 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 0b8ae73b0466..86e78bbd2e4e 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -196,10 +196,11 @@ static struct usb_port *find_default_peer(struct usb_hub *hub, int port1)
return peer;
}
-static void link_peers(struct usb_port *left, struct usb_port *right)
+static int link_peers(struct usb_port *left, struct usb_port *right)
{
struct device *rdev;
struct device *ldev;
+ int rc;
if (left->peer) {
right = left->peer;
@@ -209,7 +210,7 @@ static void link_peers(struct usb_port *left, struct usb_port *right)
WARN_ONCE(1, "%s port%d already peered with %s %d\n",
dev_name(ldev), left->portnum, dev_name(rdev),
right->portnum);
- return;
+ return -EBUSY;
} else if (right->peer) {
left = right->peer;
ldev = left->dev.parent->parent;
@@ -218,13 +219,43 @@ static void link_peers(struct usb_port *left, struct usb_port *right)
WARN_ONCE(1, "%s port%d already peered with %s %d\n",
dev_name(rdev), right->portnum, dev_name(ldev),
left->portnum);
- return;
+ 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;
}
get_device(&right->dev);
left->peer = right;
get_device(&left->dev);
right->peer = left;
+
+ return 0;
+}
+
+static void link_peers_report(struct usb_port *left, struct usb_port *right)
+{
+ struct device *rdev = right->dev.parent->parent;
+ struct device *ldev = left->dev.parent->parent;
+ int rc;
+
+ rc = link_peers(left, right);
+ if (rc == 0) {
+ pr_debug("usb: link %s port%d to %s port%d\n",
+ dev_name(ldev), left->portnum,
+ dev_name(rdev), right->portnum);
+ } else {
+ pr_warn("usb: failed to link %s port%d to %s port%d (%d)\n",
+ dev_name(ldev), left->portnum,
+ dev_name(rdev), right->portnum, rc);
+ pr_warn_once("usb: port power management may be unreliable\n");
+ }
}
static void unlink_peers(struct usb_port *left, struct usb_port *right)
@@ -236,8 +267,10 @@ static void unlink_peers(struct usb_port *left, struct usb_port *right)
"%s port%d and %s port%d are not peers?\n",
dev_name(ldev), left->portnum, dev_name(rdev), right->portnum);
+ sysfs_remove_link(&left->dev.kobj, "peer");
put_device(&left->dev);
right->peer = NULL;
+ sysfs_remove_link(&right->dev.kobj, "peer");
put_device(&right->dev);
left->peer = NULL;
}
@@ -306,7 +339,7 @@ static struct usb_port *do_default_link(struct usb_port *port_dev, void *p)
* set
*/
if (peer && !port_dev->peer)
- link_peers(port_dev, peer);
+ link_peers_report(port_dev, peer);
return NULL;
}
@@ -372,7 +405,7 @@ void usb_set_hub_port_location(struct usb_device *hdev, int port1,
enum_peer = 1;
}
- link_peers(port_dev, peer);
+ link_peers_report(port_dev, peer);
/*
* If a peer relationship was invalidated then we need to
@@ -414,7 +447,7 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
struct usb_port *peer = find_default_peer(hub, port1);
if (peer)
- link_peers(port_dev, peer);
+ link_peers_report(port_dev, peer);
}
mutex_unlock(&peer_lock);
--
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