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8250: use callbacks to access UART_DLL/UART_DLM

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Some UART HW has a single register combining UART_DLL/UART_DLM
(this was probably forgotten in the change that introduced the
callbacks, commit b32b19b8ff)

Fixes: b32b19b8ff ("[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>
This commit is contained in:
Sebastian Frias 2015-12-18 17:40:05 +01:00 • committed by Greg Kroah-Hartman
parent aaa68c50b2
commit 0b41ce9910
1 changed files with 6 additions and 12 deletions
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18
drivers/tty/serial/8250/8250_port.c
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@ -813,22 +813,16 @@ 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;