linux-kernel - [PATCH] serial: imx: remove a redundant check

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Message-Id: <20230211154550.2130670-1-trix@redhat.com>
Date:   Sat, 11 Feb 2023 07:45:50 -0800
From:   Tom Rix <trix@...hat.com>
To:     gregkh@...uxfoundation.org, jirislaby@...nel.org,
        shawnguo@...nel.org, s.hauer@...gutronix.de, kernel@...gutronix.de,
        festevam@...il.com, linux-imx@....com
Cc:     linux-serial@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Tom Rix <trix@...hat.com>
Subject: [PATCH] serial: imx: remove a redundant check

cpp_check reports
drivers/tty/serial/imx.c:1207:15: style: Condition 'r_bytes>0' is always true [knownConditionTrueFalse]
  if (r_bytes > 0) {

r_byte is set to
  r_bytes = rx_ring->head - rx_ring->tail;

The head - tail calculation is also done by the earlier check
  if (rx_ring->head <= sg_dma_len(sgl) &&
      rx_ring->head > rx_ring->tail) {

so r_bytes will always be > 0, so the second check is not needed.

Signed-off-by: Tom Rix <trix@...hat.com>
---
 drivers/tty/serial/imx.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 363c77a140f0..523f296d5747 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1204,11 +1204,9 @@ static void imx_uart_dma_rx_callback(void *data)
 		r_bytes = rx_ring->head - rx_ring->tail;
 
 		/* If we received something, check for 0xff flood */
-		if (r_bytes > 0) {
-			spin_lock(&sport->port.lock);
-			imx_uart_check_flood(sport, imx_uart_readl(sport, USR2));
-			spin_unlock(&sport->port.lock);
-		}
+		spin_lock(&sport->port.lock);
+		imx_uart_check_flood(sport, imx_uart_readl(sport, USR2));
+		spin_unlock(&sport->port.lock);
 
 		if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
 
-- 
2.26.3