From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Frias Subject: [PATCH v3] use callbacks to access UART_DLL/UART_DLM Date: Fri, 18 Dec 2015 17:40:05 +0100 Message-ID: <567436E5.8020607@laposte.net> References: <5672D89A.4090307@laposte.net> <5672F9C9.1010601@laposte.net> <5673E3FD.8080001@laposte.net> <56742F23.5010501@hurleysoftware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56742F23.5010501@hurleysoftware.com> Sender: linux-kernel-owner@vger.kernel.org To: Peter Hurley Cc: Greg Kroah-Hartman , =?UTF-8?B?TcOlbnMgUnU=?= =?UTF-8?B?bGxnw6VyZA==?= , linux-serial@vger.kernel.org, LKML , Mason , Jon Anders Haugum List-Id: linux-serial@vger.kernel.org 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 --- drivers/tty/serial/8250/8250_port.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 52d82d2..56ccbce 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -713,22 +713,16 @@ 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; -- 1.7.10.4