[PATCH v2 1/6] serial: 8250: Use defined IER bits

From: Ilpo Järvinen
Date: Fri Nov 25 2022 - 08:05:37 EST


Instead of literal 0x0f, add a define for enabling all IER bits the
8250 driver is interested in.

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 | 10 +++++-----
include/linux/serial.h | 5 +++++
2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index beba8f38b3dc..8676f8b7f2e3 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1236,14 +1236,14 @@ static void autoconfig(struct uart_8250_port *up)
* Mask out IER[7:4] bits for test as some UARTs (e.g. TL
* 16C754B) allow only to modify them if an EFR bit is set.
*/
- scratch2 = serial_in(up, UART_IER) & 0x0f;
- serial_out(up, UART_IER, 0x0F);
+ scratch2 = serial_in(up, UART_IER) & UART_IER_ALL_INTR;
+ serial_out(up, UART_IER, UART_IER_ALL_INTR);
#ifdef __i386__
outb(0, 0x080);
#endif
- scratch3 = serial_in(up, UART_IER) & 0x0f;
+ scratch3 = serial_in(up, UART_IER) & UART_IER_ALL_INTR;
serial_out(up, UART_IER, scratch);
- if (scratch2 != 0 || scratch3 != 0x0F) {
+ if (scratch2 != 0 || scratch3 != UART_IER_ALL_INTR) {
/*
* We failed; there's nothing here
*/
@@ -1394,7 +1394,7 @@ static void autoconfig_irq(struct uart_8250_port *up)
serial8250_out_MCR(up,
UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
}
- serial_out(up, UART_IER, 0x0f); /* enable all intrs */
+ serial_out(up, UART_IER, UART_IER_ALL_INTR);
serial_in(up, UART_LSR);
serial_in(up, UART_RX);
serial_in(up, UART_IIR);
diff --git a/include/linux/serial.h b/include/linux/serial.h
index 3d6fe3ef92cf..ad6e1c37e2d5 100644
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -12,6 +12,11 @@
#include <uapi/linux/serial.h>
#include <uapi/linux/serial_reg.h>

+#define UART_IER_ALL_INTR (UART_IER_MSI | \
+ UART_IER_RLSI | \
+ UART_IER_THRI | \
+ UART_IER_RDI)
+
/* Helper for dealing with UART_LCR_WLEN* defines */
#define UART_LCR_WLEN(x) ((x) - 5)

--
2.30.2