[PATCH v2 2/6] serial: 8250: Name MSR literals

From: Ilpo Järvinen
Date: Fri Nov 25 2022 - 08:05:35 EST


Add UART_MSR_STATUS_BITS for CD, RI, DSR & CTS. Use names for the
literal.

Don't make the define for combined flags part of UAPI.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_port.c | 4 ++--
include/linux/serial.h | 5 +++++
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 8676f8b7f2e3..c870ee8e80b6 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1268,9 +1268,9 @@ static void autoconfig(struct uart_8250_port *up)
*/
if (!(port->flags & UPF_SKIP_TEST)) {
serial8250_out_MCR(up, UART_MCR_LOOP | 0x0A);
- status1 = serial_in(up, UART_MSR) & 0xF0;
+ status1 = serial_in(up, UART_MSR) & UART_MSR_STATUS_BITS;
serial8250_out_MCR(up, save_mcr);
- if (status1 != 0x90) {
+ if (status1 != (UART_MSR_DCD | UART_MSR_CTS)) {
spin_unlock_irqrestore(&port->lock, flags);
DEBUG_AUTOCONF("LOOP test failed (%02x) ",
status1);
diff --git a/include/linux/serial.h b/include/linux/serial.h
index ad6e1c37e2d5..bfda927dde15 100644
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -28,6 +28,11 @@ static inline bool uart_lsr_tx_empty(u16 lsr)
return (lsr & UART_LSR_BOTH_EMPTY) == UART_LSR_BOTH_EMPTY;
}

+#define UART_MSR_STATUS_BITS (UART_MSR_DCD | \
+ UART_MSR_RI | \
+ UART_MSR_DSR | \
+ UART_MSR_CTS)
+
/*
* Counters of the input lines (CTS, DSR, RI, CD) interrupts
*/
--
2.30.2