mirros/rockchip-kernel
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

usb: assign default peer ports for root hubs

Browse Source 
Assume that the peer of a superspeed port is the port with the same id
on the shared_hcd root hub.  This identification scheme is required of
external hubs by the USB3 spec [1].  However, for root hubs, tier mismatch
may be in effect [2].  Tier mismatch can only be enumerated via platform
firmware.  For now, simply perform the nominal association.

A new lock 'usb_port_peer_mutex' is introduced to synchronize port
device add/remove with peer lookups.  It protects peering against
changes to hcd->shared_hcd, hcd->self.root_hub, hdev->maxchild, and
port_dev->child pointers.

[1]: usb 3.1 section 10.3.3
[2]: xhci 1.1 appendix D

Cc: Alan Stern <stern@rowland.harvard.edu>
[alan: usb_port_peer_mutex locking scheme]
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>
This commit is contained in:
Dan Williams
2014-05-20 18:08:28 -07:00
committed by Greg Kroah-Hartman
parent a4204ff0bd
commit d8521afe35
5 changed files with 134 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/usb/core/hub.h
View File

@@ -82,6 +82,7 @@ struct usb_hub {
* @child: usb device attached to the port
* @dev: generic device interface
* @port_owner: port's owner
* @peer: related usb2 and usb3 ports (share the same connector)
* @connect_type: port's connect type
* @portnum: port index num based one
* @power_is_on: port's power state
@@ -91,6 +92,7 @@ struct usb_port {
struct usb_device *child;
struct device dev;
struct usb_dev_state *port_owner;
struct usb_port *peer;
enum usb_port_connect_type connect_type;
u8 portnum;
unsigned power_is_on:1;