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Commit b7e38eac authored by Dan Williams's avatar Dan Williams Committed by Greg Kroah-Hartman
Browse files

usb: sysfs link peer ports 



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: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3bfd659b

drivers/usb/core/port.c

+34 −5
Original line number Diff line number Diff line
@@ -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)