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path: root/drivers/tty/serial/8250/8250_core.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_core.c')
-rw-r--r--drivers/tty/serial/8250/8250_core.c18
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 e5c31eadb0ac..04da6f0e3326 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -738,22 +738,16 @@ 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;