[PATCH v3 09/12] serial: 8250: make saved LSR larger

From: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
To: linux-serial@vger.kernel.org,
	Greg KH <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>, Lukas Wunner <lukas@wunner.de>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Johan Hovold" <johan@kernel.org>,
	heiko@sntech.de, giulio.benetti@micronovasrl.com,
	"Heikki Krogerus" <heikki.krogerus@linux.intel.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH v3 09/12] serial: 8250: make saved LSR larger
Date: Mon, 11 Apr 2022 11:33:18 +0300	[thread overview]
Message-ID: <20220411083321.9131-10-ilpo.jarvinen@linux.intel.com> (raw)
In-Reply-To: <20220411083321.9131-1-ilpo.jarvinen@linux.intel.com>

DW flags address received as BIT(8) in LSR. In order to not
lose that on read, enlarge lsr_saved_flags and adjust related
call chains which passed chars previously.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/tty/serial/8250/8250_port.c | 8 ++++----
 include/linux/serial_8250.h         | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 276c5281aaa0..6e85ad0fade6 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1585,7 +1585,7 @@ static inline void __start_tx(struct uart_port *port)
 
 	if (serial8250_set_THRI(up)) {
 		if (up->bugs & UART_BUG_TXEN) {
-			unsigned char lsr;
+			unsigned int lsr;
 
 			lsr = serial_in(up, UART_LSR);
 			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
@@ -1741,7 +1741,7 @@ 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;
@@ -1808,7 +1808,7 @@ EXPORT_SYMBOL_GPL(serial8250_read_char);
  * value, and returns the remaining LSR bits not handled
  * by this Rx routine.
  */
-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;
@@ -1930,7 +1930,7 @@ 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;
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

