[PATCH v7 1/6] serial: 8250: make saved LSR larger

Ilpo Järvinen
2022-06-15T12:49:13Z

DW flags address received as BIT(8) in LSR. In order to not lose that
on read, enlarge lsr_saved_flags to u16.

Adjust lsr/status variables and related call chains to use u16.
Technically, some of these type conversion would not be needed but it
doesn't hurt to be consistent.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
drivers/tty/serial/8250/8250.h | 4 ++--
drivers/tty/serial/8250/8250_exar.c | 2 +-
drivers/tty/serial/8250/8250_fsl.c | 2 +-
drivers/tty/serial/8250/8250_ingenic.c | 2 +-
drivers/tty/serial/8250/8250_omap.c | 7 +++----
drivers/tty/serial/8250/8250_port.c | 17 +++++++++--------
include/linux/serial_8250.h | 6 +++---
7 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index b120da57c61f..0ff5688ba90c 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -133,9 +133,9 @@ static inline void serial_out(struct uart_8250_port *up, int offset, int value)
*
* Returns LSR value or'ed with the preserved flags (if any).
*/
-static inline unsigned int serial_lsr_in(struct uart_8250_port *up)
+static inline u16 serial_lsr_in(struct uart_8250_port *up)
{
- unsigned int lsr = up->lsr_saved_flags;
+ u16 lsr = up->lsr_saved_flags;

lsr |= serial_in(up, UART_LSR);
up->lsr_saved_flags = lsr & LSR_SAVE_FLAGS;
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 528779b40049..8be3c9ecd623 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -195,7 +195,7 @@ static int xr17v35x_startup(struct uart_port *port)

static void exar_shutdown(struct uart_port *port)
{
- unsigned char lsr;
+ u16 lsr;
bool tx_complete = false;
struct uart_8250_port *up = up_to_u8250p(port);
struct circ_buf *xmit = &port->state->xmit;
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
index 9c01c531349d..e76b8bd3d4a1 100644
--- a/drivers/tty/serial/8250/8250_fsl.c
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -25,7 +25,7 @@

int fsl8250_handle_irq(struct uart_port *port)
{
- unsigned char lsr, orig_lsr;
+ u16 lsr, orig_lsr;
unsigned long flags;
unsigned int iir;
struct uart_8250_port *up = up_to_u8250p(port);
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index cff91aa03f29..2b2f5d8d24b9 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -54,7 +54,7 @@ static void early_out(struct uart_port *port, int offset, uint8_t value)

static void ingenic_early_console_putc(struct uart_port *port, unsigned char c)
{
- uint8_t lsr;
+ u16 lsr;

do {
lsr = early_in(port, UART_LSR);
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index ac8bfa042391..0dcecbbc3967 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -1115,8 +1115,7 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
return omap_8250_rx_dma(up);
}

-static unsigned char omap_8250_handle_rx_dma(struct uart_8250_port *up,
- u8 iir, unsigned char status)
+static u16 omap_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir, u16 status)
{
if ((status & (UART_LSR_DR | UART_LSR_BI)) &&
(iir & UART_IIR_RDI)) {
@@ -1130,7 +1129,7 @@ static unsigned char omap_8250_handle_rx_dma(struct uart_8250_port *up,
}

static void am654_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir,
- unsigned char status)
+ u16 status)
{
/*
* Queue a new transfer if FIFO has data.
@@ -1164,7 +1163,7 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
struct omap8250_priv *priv = up->port.private_data;
- unsigned char status;
+ u16 status;
u8 iir;

serial8250_rpm_get(up);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index c860f5964138..f417c29507e1 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1508,7 +1508,7 @@ static inline void __stop_tx(struct uart_8250_port *p)
struct uart_8250_em485 *em485 = p->em485;

if (em485) {
- unsigned char lsr = serial_lsr_in(p);
+ u16 lsr = serial_lsr_in(p);
u64 stop_delay = 0;

if (!(lsr & UART_LSR_THRE))
@@ -1565,7 +1565,7 @@ static inline void __start_tx(struct uart_port *port)

if (serial8250_set_THRI(up)) {
if (up->bugs & UART_BUG_TXEN) {
- unsigned char lsr = serial_lsr_in(up);
+ u16 lsr = serial_lsr_in(up);

if (lsr & UART_LSR_THRE)
serial8250_tx_chars(up);
@@ -1719,7 +1719,7 @@ static void serial8250_enable_ms(struct uart_port *port)
serial8250_rpm_put(up);
}

-void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
+void serial8250_read_char(struct uart_8250_port *up, u16 lsr)
{
struct uart_port *port = &up->port;
unsigned char ch;
@@ -1788,7 +1788,7 @@ EXPORT_SYMBOL_GPL(serial8250_read_char);
* (such as THRE) because the LSR value might come from an already consumed
* character.
*/
-unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
+u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr)
{
struct uart_port *port = &up->port;
int max_count = 256;
@@ -1908,7 +1908,7 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
*/
int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
{
- unsigned char status;
+ u16 status;
struct uart_8250_port *up = up_to_u8250p(port);
bool skip_rx = false;
unsigned long flags;
@@ -1994,7 +1994,7 @@ static unsigned int serial8250_tx_empty(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
unsigned long flags;
- unsigned int lsr;
+ u16 lsr;

serial8250_rpm_get(up);

@@ -2117,7 +2117,7 @@ static void wait_for_xmitr(struct uart_8250_port *up, int bits)
static int serial8250_get_poll_char(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
- unsigned char lsr;
+ u16 lsr;
int status;

serial8250_rpm_get(up);
@@ -2173,7 +2173,8 @@ int serial8250_do_startup(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
unsigned long flags;
- unsigned char lsr, iir;
+ unsigned char iir;
+ u16 lsr;
int retval;

if (!port->fifosize)
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index ff84a3ed10ea..4565f25ba9a2 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -119,7 +119,7 @@ struct uart_8250_port {
* be immediately processed.
*/
#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
- unsigned char lsr_saved_flags;
+ u16 lsr_saved_flags;
#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
unsigned char msr_saved_flags;

@@ -170,8 +170,8 @@ extern void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
unsigned int quot_frac);
extern int fsl8250_handle_irq(struct uart_port *port);
int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
-unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr);
-void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr);
+u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr);
+void serial8250_read_char(struct uart_8250_port *up, u16 lsr);
void serial8250_tx_chars(struct uart_8250_port *up);
unsigned int serial8250_modem_status(struct uart_8250_port *up);
void serial8250_init_port(struct uart_8250_port *up);
--
2.30.2