Rather than using a hard-coded per-character Tx-timeout of 10ms,
use the frame time to determine a timeout value. The value is
doubled to ensure that a timeout is only hit during unexpected
circumstances.
Since the frame time may not be available during early printing,
the previous 10ms value is kept as a fallback.
Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
---
drivers/tty/serial/8250/8250_port.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3a946ebe9139..ca8f6f3855eb 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2081,9 +2081,17 @@ static void serial8250_break_ctl(struct uart_port *port, int break_state)
/* Returns true if @bits were set, false on timeout */
static bool wait_for_lsr(struct uart_8250_port *up, int bits)
{
- unsigned int status, tmout = 10000;
+ unsigned int status, tmout;
+
+ /*
+ * Wait for a character to be sent. Fallback to a safe default
+ * timeout value if @frame_time is not available.
+ */
+ if (up->port.frame_time)
+ tmout = up->port.frame_time * 2 / NSEC_PER_USEC;
+ else
+ tmout = 10000;
- /* Wait up to 10ms for the character(s) to be sent. */
for (;;) {
status = serial_lsr_in(up);
--
2.39.5
