Originally Toshiba told us that the only way to disable HDCP was to
set the receiver in repeater mode, that would make the authentication
fail because of missing software support. It has worked fine with all
the sources we and our customers has used, until it was reported
problems with Apple MacBook (Retina, 12-inch, Early 2015)
(https://support.apple.com/kb/SP712?locale=en_US&viewlocale=en_US)
with Apple A1612 USB type-C multiport adapter
(http://www.apple.com/shop/product/MJ1K2AM/A/usb-c-digital-av-multiport-adapter)

Finally Toshiba came up with a hidden bit that is named "Manual HDCP
authentication". In this patch the original "repeater mode" concept is
removed, and the new bit is set instead.

With his patch HDCP is disabled when connected to the Apple MacBook
and all other sources we have tested so far. The Apple MacBook is
constantly trying to authenticate, but fails and continues to transmit
unencrypted video.
Signed-off-by: Mats Randgaard <matrandg@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>