tty: serial: samsung: Properly set flags in autoCTS mode

[ Upstream commit 31e933645742ee6719d37573a27cce0761dcf92b ]

Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support")
has changed the way the autoCTS mode is handled.

According to that change, serial drivers which enable H/W autoCTS mode must
set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling
TX. This patch adds proper handling of UPSTAT_AUTOCTS flag.

Signed-off-by: Beomho Seo <beomho.seo@samsung.com>
[mszyprow: rephrased commit message]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index 2f8fa18..c6058b5 100644 (file)
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1365,11 +1365,14 @@ static void s3c24xx_serial_set_termios(struct uart_port *port,
        wr_regl(port, S3C2410_ULCON, ulcon);
        wr_regl(port, S3C2410_UBRDIV, quot);
 
+       port->status &= ~UPSTAT_AUTOCTS;
+
        umcon = rd_regl(port, S3C2410_UMCON);
        if (termios->c_cflag & CRTSCTS) {
                umcon |= S3C2410_UMCOM_AFC;
                /* Disable RTS when RX FIFO contains 63 bytes */
                umcon &= ~S3C2412_UMCON_AFC_8;
+               port->status = UPSTAT_AUTOCTS;
        } else {
                umcon &= ~S3C2410_UMCOM_AFC;
        }