[PATCH AUTOSEL 4.9 053/141] tty: omap-serial: remove set but unused variable

[Sasha Levin]

From: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>

[ Upstream commit e83c6587c47caa2278aa3bd603b5a85eddc4cec9 ]

Fix the following warning:
drivers/tty/serial/omap-serial.c: In function serial_omap_rlsi:
drivers/tty/serial/omap-serial.c:496:16: warning: variable ch set but not used [-Wunused-but-set-variable]

The character read is useless according to the table 23-246 of the omap4
TRM. So we can drop it.

Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1575617863-32484-1-git-send-email-wangxiongfeng2@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/tty/serial/omap-serial.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 472ba3c813c1a..6045ffcb4f6d0 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -497,10 +497,13 @@ static unsigned int check_modem_status(struct uart_omap_port *up)
 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
 {
 	unsigned int flag;
-	unsigned char ch = 0;
 
+	/*
+	 * Read one data character out to avoid stalling the receiver according
+	 * to the table 23-246 of the omap4 TRM.
+	 */
 	if (likely(lsr & UART_LSR_DR))
-		ch = serial_in(up, UART_RX);
+		serial_in(up, UART_RX);
 
 	up->port.icount.rx++;
 	flag = TTY_NORMAL;
-- 
2.20.1