| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 053/177] serial: tegra: Fix a mask operation that is always true | Date | Mon, 31 May 2021 15:13:30 +0200 |
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From: Colin Ian King <colin.king@canonical.com>
commit 3ddb4ce1e6e3bd112778ab93bbd9092f23a878ec upstream.
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> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210426105514.23268-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/tty/serial/serial-tegra.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -332,7 +332,7 @@ static void tegra_uart_fifo_reset(struct 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);
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