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From:   =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
To:     linux-serial@vger.kernel.org, Greg KH <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Paul Cercueil <paul@crapouillou.net>,
        linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org
Cc:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Lukas Wunner <lukas.wunner@intel.com>,
        =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH v6 1/6] serial: 8250: make saved LSR larger
Date:   Mon, 13 Jun 2022 10:52:22 +0300
Message-Id: <20220613075227.10394-2-ilpo.jarvinen@linux.intel.com>
In-Reply-To: <20220613075227.10394-1-ilpo.jarvinen@linux.intel.com>
References: <20220613075227.10394-1-ilpo.jarvinen@linux.intel.com>
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Precedence: bulk

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 which used unsigned
char type previously to unsigned int. 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_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    |  8 ++++----
 drivers/tty/serial/8250/8250_port.c    | 15 ++++++++-------
 include/linux/serial_8250.h            |  6 +++---
 6 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 528779b40049..0eae2d8a9494 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;
+	unsigned int 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..fde48527caab 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;
+	unsigned int 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..1f247a270b17 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;
+	unsigned int 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..f0114eca9095 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -1115,8 +1115,8 @@ 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 unsigned int omap_8250_handle_rx_dma(struct uart_8250_port *up,
+					    u8 iir, unsigned int status)
 {
 	if ((status & (UART_LSR_DR | UART_LSR_BI)) &&
 	    (iir & UART_IIR_RDI)) {
@@ -1130,7 +1130,7 @@ 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)
+				     unsigned int status)
 {
 	/*
 	 * Queue a new transfer if FIFO has data.
@@ -1164,7 +1164,7 @@ 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;
+	unsigned int 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..8ff9f4815c7b 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);
+		unsigned int 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);
+			unsigned int 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, unsigned int 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)
+unsigned int serial8250_rx_chars(struct uart_8250_port *up, unsigned int 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;
+	unsigned int status;
 	struct uart_8250_port *up = up_to_u8250p(port);
 	bool skip_rx = false;
 	unsigned long flags;
@@ -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;
+	unsigned int 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;
+	unsigned int lsr;
 	int retval;
 
 	if (!port->fifosize)
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index ff84a3ed10ea..921df4c60062 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);
+unsigned int serial8250_rx_chars(struct uart_8250_port *up, unsigned int lsr);
+void serial8250_read_char(struct uart_8250_port *up, unsigned int 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