Re: [PATCH] tty: serial: fsl_lpuart: count tty buffer overruns

From: Jiri Slaby
Date: Tue Jan 11 2022 - 02:09:03 EST


On 11. 01. 22, 7:10, Sherry Sun wrote:
Added support for counting the tty buffer overruns in fsl_lpuart driver
like other uart drivers.

Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
---
drivers/tty/serial/fsl_lpuart.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index ce3e26144689..1e6f924d8507 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
...
@@ -1117,6 +1119,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
struct circ_buf *ring = &sport->rx_ring;
unsigned long flags;
int count = 0;
+ unsigned int copied = 0;
if (lpuart_is_32(sport)) {
unsigned long sr = lpuart32_read(&sport->port, UARTSTAT);
@@ -1218,20 +1221,24 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
if (ring->head < ring->tail) {
count = sport->rx_sgl.length - ring->tail;
- tty_insert_flip_string(port, ring->buf + ring->tail, count);
+ copied = tty_insert_flip_string(port, ring->buf + ring->tail, count);
+ if (copied != count)

Overall looks good, except tty_insert_flip_string returns an int and count is also an int. Wouldn't it be more consistent to declare copied as int too? This comparison would be without implicit conversion then.

thanks,
--
js
suse labs