serial: 8250_uniphier: use CHAR register for canary to detect power-off
The 8250 core uses the SCR as a canary to discover if the console has
been powered-off.
This hardware does not have SCR at offset 7, but an unused register
CHAR at a different offset. As long as the character interrupt is
disabled, the register access has no impact, so it is useful as an
alternative scratch register.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed