tree 7049f9ac05154fc4cad5c2606ce55c2a61abdb53
parent 6ed962a208cb72cff29a107d6c73247526017ddb
author Sarah Sharp <sarah.a.sharp@linux.intel.com> 1314986740 -0700
committer Greg Kroah-Hartman <gregkh@suse.de> 1315608772 -0700

xhci: If no endpoints changed, don't issue BW command.

Some alternate interface settings have no endpoints associated with them.
This shows up in some USB webcams, particularly the Logitech HD 1080p,
which uses the uvcvideo driver.  If a driver switches between two alt
settings with no endpoints, there is no need to issue a configure endpoint
command, because there is no endpoint information to update.

The only time a configure endpoint command with just the add slot flag set
makes sense is when the driver is updating hub characteristics in the slot
context.  However, that code never calls xhci_check_bandwidth, so we
should be safe not issuing a command if only the slot context add flag is
set.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>