This avoids mangling with registers when reading the RS485 status via IOCTL.
Also, features can check their configuration at runtime which will be needed
for a later patch.
Signed-off-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
---
drivers/tty/serial/8250.c | 16 +++++-----------
1 files changed, 5 insertions(+), 11 deletions(-)
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index 920b4df..b5d3248 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -154,6 +154,7 @@ struct uart_8250_port {
unsigned char lsr_saved_flags;
#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
unsigned char msr_saved_flags;
+ __u32 rs485_flags; /* copied from IOCTL */
};
struct irq_info {
@@ -2729,28 +2730,21 @@ static int serial8250_ioctl_port(struct uart_port *port,
serial_outp(up, UART_FCTR, fctr);
serial_outp(up, UART_LCR, lcr);
spin_unlock_irqrestore(&up->port.lock, flags);
+
+ up->rs485_flags = rs485ctrl.flags;
+
return 0;
}
case TIOCGRS485:
{
struct serial_rs485 rs485ctrl;
- unsigned char lcr;
if (port->type != PORT_16850)
return -ENOTTY;
memset(&rs485ctrl, 0, sizeof(rs485ctrl));
-
- spin_lock_irqsave(&up->port.lock, flags);
- lcr = serial_inp(up, UART_LCR);
- serial_outp(up, UART_LCR, UART_LCR_CONF_MODE_B);
- if (serial_inp(up, UART_FCTR) & UART_FCTR_RS485)
- rs485ctrl.flags = SER_RS485_ENABLED;
- else
- rs485ctrl.flags = 0;
- serial_outp(up, UART_LCR, lcr);
- spin_unlock_irqrestore(&up->port.lock, flags);
+ rs485ctrl.flags = up->rs485_flags;
if (copy_to_user((struct serial_rs485 *)arg, &rs485ctrl,
sizeof(rs485ctrl)))
--
1.7.7.1
--
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