From 5a8c296f5362fffc9da5da10eef01cf0b9b4ac7f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christoph=20Vogtl=C3=A4nder?= Date: Wed, 4 Sep 2019 14:11:41 +0200 Subject: [PATCH] serial: max310x: Properly set flags in AutoCTS mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 391f93f2ec9f ("serial: core: Rework hw-assisted 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_AUTORTS, UPSTAT_AUTOCTS and UPSTAT_AUTOXOFF to prevent the serial core from inadvertently disabling RX or TX. This patch adds proper handling of UPSTAT_AUTORTS, UPSTAT_AUTOCTS and UPSTAT_AUTOXOFF flags. Signed-off-by: Christoph VogtlÃĪnder Link: https://lore.kernel.org/r/20190904121141.4570-1-c.vogtlaender@sigma-surface-science.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/max310x.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index 0e0c2740ec7e..aed19c688beb 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -955,15 +955,23 @@ static void max310x_set_termios(struct uart_port *port, /* Configure flow control */ max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]); max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]); - if (termios->c_cflag & CRTSCTS) + + port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF); + + if (termios->c_cflag & CRTSCTS) { + /* Enable AUTORTS and AUTOCTS */ + port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; flow |= MAX310X_FLOWCTRL_AUTOCTS_BIT | MAX310X_FLOWCTRL_AUTORTS_BIT; + } if (termios->c_iflag & IXON) flow |= MAX310X_FLOWCTRL_SWFLOW3_BIT | MAX310X_FLOWCTRL_SWFLOWEN_BIT; - if (termios->c_iflag & IXOFF) + if (termios->c_iflag & IXOFF) { + port->status |= UPSTAT_AUTOXOFF; flow |= MAX310X_FLOWCTRL_SWFLOW1_BIT | MAX310X_FLOWCTRL_SWFLOWEN_BIT; + } max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow); /* Get baud rate generator configuration */