PS2_FLAG_ACK
ps2dev->flags |= PS2_FLAG_ACK;
ps2dev->flags &= ~PS2_FLAG_ACK;
if (old_flags & PS2_FLAG_ACK)
if (old_flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
if (ps2dev->flags & PS2_FLAG_ACK)
!(ps2dev->flags & PS2_FLAG_ACK),
ps2dev->flags &= ~PS2_FLAG_ACK;