From 04eadffff87a474dd70272f45baa9bbfe9794d8b Mon Sep 17 00:00:00 2001 From: Tudor Ambarus <tudor.ambarus@linaro.org> Date: Fri, 19 Jan 2024 10:45:08 +0000 Subject: [PATCH] tty: serial: samsung: fix tx_empty() to return TIOCSER_TEMT [ Upstream commit 314c2b399288f0058a8c5b6683292cbde5f1531b ] The core expects for tx_empty() either TIOCSER_TEMT when the tx is empty or 0 otherwise. s3c24xx_serial_txempty_nofifo() might return 0x4, and at least uart_get_lsr_info() tries to clear exactly TIOCSER_TEMT (BIT(1)). Fix tx_empty() to return TIOCSER_TEMT. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org> Link: https://lore.kernel.org/r/20240119104526.1221243-2-tudor.ambarus@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/tty/serial/samsung_tty.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 7a0cc1dc3..0c963590b 100755 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -922,11 +922,10 @@ static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port) if ((ufstat & info->tx_fifomask) != 0 || (ufstat & info->tx_fifofull)) return 0; - - return 1; + return TIOCSER_TEMT; } - return s3c24xx_serial_txempty_nofifo(port); + return s3c24xx_serial_txempty_nofifo(port) ? TIOCSER_TEMT : 0; } /* no modem control lines */