xhci: A default implementation for Ux timeout calculation and tier policy check
authorPratyush Anand <pratyush.anand@st.com>
Fri, 4 Jul 2014 14:01:23 +0000 (17:01 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 9 Jul 2014 22:41:34 +0000 (15:41 -0700)
commit9502c46cc9d39330b29d9dc27d8baff4f55d0abc
tree0bb78702768f662bdef5537e9b7a3bdf983deb53
parentec5734c41bee2ee7c938a8f34853d31cada7e67a
xhci: A default implementation for Ux timeout calculation and tier policy check

As best case, a host controller should support U0 to U1 switching for
the devices connected below any tier of hub level supported by usb
specification. Therefore xhci_check_tier_policy should always return
success as default implementation.

A host should be able to issue LGO_Ux after the timeout calculated as
per definition of system exit latency defined in C.1.5.2. Therefore
xhci_calculate_ux_timeout returns ux_params.sel as the default
implementation.

Use default calculation in absence of any vendor specific limitations.

Signed-off-by: Pratyush Anand <pratyush.anand@st.com>
Tested-by: Aymen Bouattay <aymen.bouattay@st.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/xhci.c