1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/mmc/card/sdio_uart.c b/drivers/mmc/card/sdio_uart.c
index 2a13db54ffc4..f53755533e7e 100644
--- a/drivers/mmc/card/sdio_uart.c
+++ b/drivers/mmc/card/sdio_uart.c
@@ -603,10 +603,14 @@ static void uart_dtr_rts(struct tty_port *tport, int onoff)
 {
         struct sdio_uart_port *port =
                         container_of(tport, struct sdio_uart_port, port);
+        int ret = sdio_uart_claim_func(port);
+        if (ret)
+                return;
         if (onoff == 0)
                 sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
         else
                 sdio_uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
+        sdio_uart_release_func(port);
 }
 
 /**