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path: root/drivers/tty/serial/amba-pl011.c
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Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
-rw-r--r--drivers/tty/serial/amba-pl011.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 51ecb050ae40..4d11a3e547f9 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1255,13 +1255,18 @@ static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
static void pl011_rs485_tx_stop(struct uart_amba_port *uap)
{
+ /*
+ * To be on the safe side only time out after twice as many iterations
+ * as fifo size.
+ */
+ const int MAX_TX_DRAIN_ITERS = uap->port.fifosize * 2;
struct uart_port *port = &uap->port;
int i = 0;
u32 cr;
/* Wait until hardware tx queue is empty */
while (!pl011_tx_empty(port)) {
- if (i == port->fifosize) {
+ if (i > MAX_TX_DRAIN_ITERS) {
dev_warn(port->dev,
"timeout while draining hardware tx queue\n");
break;
@@ -2052,7 +2057,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
* with the given baud rate. We use this as the poll interval when we
* wait for the tx queue to empty.
*/
- uap->rs485_tx_drain_interval = (bits * 1000 * 1000) / baud;
+ uap->rs485_tx_drain_interval = DIV_ROUND_UP(bits * 1000 * 1000, baud);
pl011_setup_status_masks(port, termios);