Commit 8b1ba80c authored by Dan Williams's avatar Dan Williams Committed by Greg Kroah-Hartman
Browse files

usb: assign usb3 external hub port peers 



Given that root hub port peers are already established, external hub peer
ports can be determined by traversing the device topology:

1/ ascend to the parent hub and find the upstream port_dev

2/ walk ->peer to find the peer port

3/ descend to the peer hub via ->child

4/ find the port with the matching port id

Note that this assumes the port labeling scheme required by the
specification [1].

[1]: usb3 3.1 section 10.3.3

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 d8521afe

drivers/usb/core/port.c

+24 −8
Original line number Diff line number Diff line
@@ -187,15 +187,18 @@ static void unlink_peers(struct usb_port *left, struct usb_port *right) 
	left->peer = NULL;

}



/* set the default peer port for root hubs */

/*

 * Set the default peer port for root hubs, or via 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 (!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->shared_hcd;
@@ -203,16 +206,29 @@ static void find_and_link_peer(struct usb_hub *hub, int port1) 
			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;



	peer = peer_hub->ports[port1 - 1];



	if (peer)

		link_peers(port_dev, peer);

}

}



int usb_hub_create_port_device(struct usb_hub *hub, int port1)

{

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