USB: add usb_hcd_{start,end}_port_resume

This patch (as1649) adds a mechanism for host controller drivers to
inform usbcore when they have begun or ended resume signalling on a
particular root-hub port.  The core will then make sure that the root
hub does not get runtime-suspended while the port resume is going on.

Since commit 596d789a21 (USB: set hub's
default autosuspend delay as 0), the system tries to suspend hubs
whenever they aren't in use.  While a root-hub port is being resumed,
the root hub does not appear to be in use.  Attempted runtime suspends
fail because of the ongoing port resume, but the PM core just keeps on
trying over and over again.  We want to prevent this wasteful effort.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alan Stern
2013-01-25 17:09:42 -05:00
committed by Greg Kroah-Hartman
parent 6e0c3339a6
commit da0aa7169b
3 changed files with 49 additions and 0 deletions

View File

@@ -357,6 +357,8 @@ struct usb_bus {
int bandwidth_int_reqs; /* number of Interrupt requests */
int bandwidth_isoc_reqs; /* number of Isoc. requests */
unsigned resuming_ports; /* bit array: resuming root-hub ports */
#if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
struct mon_bus *mon_bus; /* non-null when associated */
int monitored; /* non-zero when monitored */