Whilst autopoll is enabled it is necessary to prevent the ADB buffer contents
from being overwritten until the host has read back the response in its
entirety.
Add adb_autopoll_block() and adb_autopoll_unblock() functions in preparation
for ensuring that the ADB buffer contents are protected for explicit ADB
requests.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200623204936.24064-16-mark.cave-ayland@ilande.co.uk>