1 files changed, 17 insertions, 18 deletions

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index a1c6519837a4..f02934ffb329 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1407,6 +1407,18 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
         /* ask the core to calculate the divisor */
         baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
 
+        /*
+         * Need to update the Ring buffer length according to the selected
+         * baud rate and restart Rx DMA path.
+         *
+         * Since timer function acqures sport->port.lock, need to stop before
+         * acquring same lock because otherwise del_timer_sync() can deadlock.
+         */
+        if (old && sport->lpuart_dma_rx_use) {
+                del_timer_sync(&sport->lpuart_timer);
+                lpuart_dma_rx_free(&sport->port);
+        }
+
         spin_lock_irqsave(&sport->port.lock, flags);
 
         sport->port.read_status_mask = 0;
@@ -1456,22 +1468,11 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
         /* restore control register */
         writeb(old_cr2, sport->port.membase + UARTCR2);
 
-        /*
-         * If new baud rate is set, we will also need to update the Ring buffer
-         * length according to the selected baud rate and restart Rx DMA path.
-         */
-        if (old) {
-                if (sport->lpuart_dma_rx_use) {
-                        del_timer_sync(&sport->lpuart_timer);
-                        lpuart_dma_rx_free(&sport->port);
-                }
-
-                if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
-                        sport->lpuart_dma_rx_use = true;
+        if (old && sport->lpuart_dma_rx_use) {
+                if (!lpuart_start_rx_dma(sport))
                         rx_dma_timer_init(sport);
-                } else {
+                else
                         sport->lpuart_dma_rx_use = false;
-                }
         }
 
         spin_unlock_irqrestore(&sport->port.lock, flags);
@@ -2131,12 +2132,10 @@ static int lpuart_resume(struct device *dev)
 
         if (sport->lpuart_dma_rx_use) {
                 if (sport->port.irq_wake) {
-                        if (!lpuart_start_rx_dma(sport)) {
-                                sport->lpuart_dma_rx_use = true;
+                        if (!lpuart_start_rx_dma(sport))
                                 rx_dma_timer_init(sport);
-                        } else {
+                        else
                                 sport->lpuart_dma_rx_use = false;
-                        }
                 }
         }