tty: omap-serial: remove set but unused variable

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@huawei.com>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Link: https://lore.kernel.org/r/1575617863-32484-1-git-send-email-wangxiongfeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 6420ae581a802fe3c614591dce7ded443e0610a6..5f808d8dfcd5c1e9d4ca56a71c20dc8dc0f76732 100644 (file)
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -493,10 +493,13 @@ 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;