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From: Colin King <colin.king@canonical.com>
To: Laxman Dewangan <ldewangan@nvidia.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Krishna Yarlagadda <kyarlagadda@nvidia.com>,
	Shardar Shariff Md <smohammed@nvidia.com>,
	linux-serial@vger.kernel.org, linux-tegra@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] serial: tegra: Fix a mask operation that is always true
Date: Mon, 26 Apr 2021 11:55:14 +0100	[thread overview]
Message-ID: <20210426105514.23268-1-colin.king@canonical.com> (raw)

From: Colin Ian King <colin.king@canonical.com>

Currently the expression lsr | UART_LSR_TEMT is always true and
this seems suspect. I believe the intent was to mask lsr with UART_LSR_TEMT
to check that bit, so the expression should be using the & operator
instead. Fix this.

Fixes: b9c2470fb150 ("serial: tegra: flush the RX fifo on frame error")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/tty/serial/serial-tegra.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index bbae072a125d..222032792d6c 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -338,7 +338,7 @@ static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
 
 	do {
 		lsr = tegra_uart_read(tup, UART_LSR);
-		if ((lsr | UART_LSR_TEMT) && !(lsr & UART_LSR_DR))
+		if ((lsr & UART_LSR_TEMT) && !(lsr & UART_LSR_DR))
 			break;
 		udelay(1);
 	} while (--tmout);
-- 
2.30.2


                 reply	other threads:[~2021-04-26 10:55 UTC|newest]

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