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From: "Christoph Vogtländer" <Christoph.Vogtlaender@sigma-surface-science.com>
To: unlisted-recipients:; (no To-header on input)
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Jiri Slaby" <jslaby@suse.com>,
	"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Christoph Vogtländer"
	<Christoph.Vogtlaender@sigma-surface-science.com>
Subject: [PATCH] serial: max310x: Properly set flags in AutoCTS mode
Date: Fri, 30 Aug 2019 09:58:34 +0000	[thread overview]
Message-ID: <47a1918df72a4b28b124a53e055e045a@SSSDEEX.i.sigma-surface-science.com> (raw)

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 Vogtländer <c.vogtlaender@sigma-surface-science.com>
---
 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 0e24235..fb5a7e0 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -859,15 +859,23 @@ 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 */
--
2.7.4


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             reply	other threads:[~2019-08-30 10:07 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-30  9:58 Christoph Vogtländer [this message]
2019-09-04  7:30 ` [PATCH] serial: max310x: Properly set flags in AutoCTS mode Greg Kroah-Hartman
2019-09-04 12:11   ` Christoph Vogtländer

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