diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2014-05-20 18:08:33 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-27 16:38:52 -0700 |
| commit | 8b1ba80c59fb3e77f9e1761480617d5ea9ee159c (patch) | |
| tree | 120b54fcb3cf3d97d6798bd41d19b2b725554bab /drivers/usb/core | |
| parent | d8521afe35862f4fbe3ccd6ca37897c0a304edf3 (diff) | |
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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/port.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c index 5ecdbf31dfcb..9b7496b52f2a 100644 --- a/drivers/usb/core/port.c +++ b/drivers/usb/core/port.c @@ -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; @@ -203,15 +206,28 @@ static void find_and_link_peer(struct usb_hub *hub, int port1) return; peer_hdev = peer_hcd->self.root_hub; - peer_hub = usb_hub_to_struct_hub(peer_hdev); - if (!peer_hub || port1 > peer_hdev->maxchild) + } 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; - peer = peer_hub->ports[port1 - 1]; + upstream = parent_hub->ports[hdev->portnum - 1]; + if (!upstream || !upstream->peer) + return; - if (peer) - link_peers(port_dev, peer); + 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) |