diff options
| author | Sebastian Frias <sf84@laposte.net> | 2015-12-18 17:40:05 +0100 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-07-10 23:06:55 -0400 |
| commit | c6aa8bae477bf2fdaacbc8683f5801511aa3b859 (patch) | |
| tree | 91c60e9916a212a3de0c7bdaf0c0e1b57f78fe14 /drivers/tty | |
| parent | e4e503b2a3c6ad22375010933041f05b2ef00367 (diff) | |
8250: use callbacks to access UART_DLL/UART_DLM
[ Upstream commit 0b41ce991052022c030fd868e03877700220b090 ]
Some UART HW has a single register combining UART_DLL/UART_DLM
(this was probably forgotten in the change that introduced the
callbacks, commit b32b19b8ffc05cbd3bf91c65e205f6a912ca15d9)
Fixes: b32b19b8ffc0 ("[SERIAL] 8250: set divisor register correctly ...")
Signed-off-by: Sebastian Frias <sf84@laposte.net>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index b4fd8debf941..a64d53f7b1d1 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -791,22 +791,16 @@ static int size_fifo(struct uart_8250_port *up) */ static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p) { - unsigned char old_dll, old_dlm, old_lcr; - unsigned int id; + unsigned char old_lcr; + unsigned int id, old_dl; old_lcr = serial_in(p, UART_LCR); serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A); + old_dl = serial_dl_read(p); + serial_dl_write(p, 0); + id = serial_dl_read(p); + serial_dl_write(p, old_dl); - old_dll = serial_in(p, UART_DLL); - old_dlm = serial_in(p, UART_DLM); - - serial_out(p, UART_DLL, 0); - serial_out(p, UART_DLM, 0); - - id = serial_in(p, UART_DLL) | serial_in(p, UART_DLM) << 8; - - serial_out(p, UART_DLL, old_dll); - serial_out(p, UART_DLM, old_dlm); serial_out(p, UART_LCR, old_lcr); return id; |