The usb topology after this change will have symlinks between usb3 ports
and their usb2 peers, for example:
usb2/2-1/2-1:1.0/2-1-port1/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port1
usb2/2-1/2-1:1.0/2-1-port2/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port2
usb2/2-1/2-1:1.0/2-1-port3/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port3
usb2/2-1/2-1:1.0/2-1-port4/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port4
usb2/2-0:1.0/usb2-port1/peer => ../../../usb3/3-0:1.0/usb3-port1
usb2/2-0:1.0/usb2-port2/peer => ../../../usb3/3-0:1.0/usb3-port2
usb2/2-0:1.0/usb2-port3/peer => ../../../usb3/3-0:1.0/usb3-port3
usb2/2-0:1.0/usb2-port4/peer => ../../../usb3/3-0:1.0/usb3-port4
usb3/3-1/3-1:1.0/usb3-1-port1/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port1
usb3/3-1/3-1:1.0/usb3-1-port2/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port2
usb3/3-1/3-1:1.0/usb3-1-port3/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port3
usb3/3-1/3-1:1.0/usb3-1-port4/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port4
usb3/3-0:1.0/usb3-port1/peer => ../../../usb2/2-0:1.0/usb2-port1
usb3/3-0:1.0/usb3-port2/peer => ../../../usb2/2-0:1.0/usb2-port2
usb3/3-0:1.0/usb3-port3/peer => ../../../usb2/2-0:1.0/usb2-port3
usb3/3-0:1.0/usb3-port4/peer => ../../../usb2/2-0:1.0/usb2-port4
Introduce link_peers_report() to notify on all link_peers() failure
cases.
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/core/port.c | 39 ++++++++++++++++++++++++++++++++++-----
1 files changed, 34 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index aea54e8dfe47..40c3ac173e9e 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -157,10 +157,12 @@ static struct device_driver usb_port_driver = {
.owner = THIS_MODULE,
};
-static void link_peers(struct usb_port *left, struct usb_port *right)
+static int link_peers(struct usb_port *left, struct usb_port *right)
{
+ int rc;
+
if (left->peer == right && right->peer == left)
- return;
+ return 0;
if (left->peer || right->peer) {
struct usb_port *lpeer = left->peer;
@@ -170,11 +172,36 @@ static void link_peers(struct usb_port *left, struct usb_port *right)
dev_name(&left->dev), dev_name(&right->dev),
dev_name(&left->dev), lpeer,
dev_name(&right->dev), rpeer);
- 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;
}
left->peer = right;
right->peer = left;
+
+ 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)
@@ -183,7 +210,9 @@ static void unlink_peers(struct usb_port *left, struct usb_port *right)
"%s and %s are not peers?\n",
dev_name(&left->dev), dev_name(&right->dev));
+ sysfs_remove_link(&left->dev.kobj, "peer");
right->peer = NULL;
+ sysfs_remove_link(&right->dev.kobj, "peer");
left->peer = NULL;
}
@@ -212,7 +241,7 @@ 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) {
- link_peers(port_dev, peer);
+ link_peers_report(port_dev, peer);
return 1; /* done */
}
}
@@ -275,7 +304,7 @@ static void find_and_link_peer(struct usb_hub *hub, int port1)
*/
peer = peer_hub->ports[port1 - 1];
if (peer && peer->location == 0)
- link_peers(port_dev, peer);
+ link_peers_report(port_dev, peer);
}
int usb_hub_create_port_device(struct usb_hub *hub, int port1)
--
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