tree 6db5a7e195068fc4ca20651a23f20a2b0350295e
parent cd52d1ee9a92587b242d946a2300a3245d3b885a
author Lennert Buytenhek <buytenh@wantstofly.org> 1131832685 +0000
committer Russell King <rmk+kernel@arm.linux.org.uk> 1131832685 +0000

[SERIAL] don't disable xscale serial ports after autoconfig

xscale-type UARTs have an extra bit (UUE) in the IER register that has
to be written as 1 to enable the UART.  At the end of autoconfig() in
drivers/serial/8250.c, the IER register is unconditionally written as
zero, which turns off the UART, and makes any subsequent printch() hang
the box.

Since other 8250-type UARTs don't have this enable bit and are thus
always 'enabled' in this sense, it can't hurt to enable xscale-type
serial ports all the time as well.  The attached patch changes the
autoconfig() exit path to see if the port has an UUE enable bit, and if
yes, to write UUE=1 instead of just putting a zero into IER, using the
same test as is used at the beginning of serial8250_console_write().

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>