From: Wolfram Sang <w.sang@pengutronix.de>
To: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Greg KH <gregkh@suse.de>,
Alan Cox <alan@linux.intel.com>,
Claudio Scordino <claudio@evidence.eu.com>,
Wolfram Sang <w.sang@pengutronix.de>,
Juergen Beisert <jbe@pengutronix.de>
Subject: [PATCH RESEND 4/8] serial: 8250: add RX_DURING_TX capability to RS485 mode
Date: Fri, 9 Dec 2011 18:07:16 +0100 [thread overview]
Message-ID: <1323450440-414-5-git-send-email-w.sang@pengutronix.de> (raw)
In-Reply-To: <1323450440-414-1-git-send-email-w.sang@pengutronix.de>
To prevent echo in some configurations, make sure we do not read back
when we are sending if RS485 is configured this way. We need to shuffle
stop_rx() around, implement start_rx() and call it in apropriate places.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
---
drivers/tty/serial/8250.c | 34 +++++++++++++++++++++++++---------
1 files changed, 25 insertions(+), 9 deletions(-)
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index b5d3248..6a2f47f 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -1304,6 +1304,26 @@ static void autoconfig_irq(struct uart_8250_port *up)
up->port.irq = (irq > 0) ? irq : 0;
}
+static void serial8250_stop_rx(struct uart_port *port)
+{
+ struct uart_8250_port *up =
+ container_of(port, struct uart_8250_port, port);
+
+ up->ier &= ~UART_IER_RLSI;
+ up->port.read_status_mask &= ~UART_LSR_DR;
+ serial_out(up, UART_IER, up->ier);
+}
+
+static void serial8250_start_rx(struct uart_port *port)
+{
+ struct uart_8250_port *up =
+ container_of(port, struct uart_8250_port, port);
+
+ up->ier |= UART_IER_RLSI;
+ up->port.read_status_mask |= UART_LSR_DR;
+ serial_out(up, UART_IER, up->ier);
+}
+
static inline void __stop_tx(struct uart_8250_port *p)
{
if (p->ier & UART_IER_THRI) {
@@ -1326,6 +1346,9 @@ static void serial8250_stop_tx(struct uart_port *port)
up->acr |= UART_ACR_TXDIS;
serial_icr_write(up, UART_ACR, up->acr);
}
+
+ if (!(up->rs485_flags & SER_RS485_RX_DURING_TX))
+ serial8250_start_rx(port);
}
static void transmit_chars(struct uart_8250_port *up);
@@ -1357,16 +1380,9 @@ static void serial8250_start_tx(struct uart_port *port)
up->acr &= ~UART_ACR_TXDIS;
serial_icr_write(up, UART_ACR, up->acr);
}
-}
-static void serial8250_stop_rx(struct uart_port *port)
-{
- struct uart_8250_port *up =
- container_of(port, struct uart_8250_port, port);
-
- up->ier &= ~UART_IER_RLSI;
- up->port.read_status_mask &= ~UART_LSR_DR;
- serial_out(up, UART_IER, up->ier);
+ if (!(up->rs485_flags & SER_RS485_RX_DURING_TX))
+ serial8250_stop_rx(port);
}
static void serial8250_enable_ms(struct uart_port *port)
--
1.7.7.3
next prev parent reply other threads:[~2011-12-09 17:07 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-09 17:07 [PATCH RESEND 0/8] serial: 8250: support hw-based RS485 direction control Wolfram Sang
2011-12-09 17:07 ` [PATCH RESEND 1/8] serial: 8250: replace hardcoded 0xbf with #define Wolfram Sang
2011-12-09 18:58 ` Alan Cox
2011-12-09 17:07 ` [PATCH RESEND 2/8] serial: 8250: Add ioctl to enable auto rs485 mode with some Exar UARTs Wolfram Sang
2011-12-09 19:00 ` Alan Cox
2011-12-09 17:07 ` [PATCH RESEND 3/8] serial: 8250: save rs485_flags per instance Wolfram Sang
2011-12-09 19:10 ` Alan Cox
2011-12-09 17:07 ` Wolfram Sang [this message]
2011-12-09 17:07 ` [PATCH RESEND 5/8] serial: 8250: reject delaying RTS with RS485 Wolfram Sang
2011-12-09 17:07 ` [PATCH RESEND 6/8] serial: 8250: update rs485 flags with polarity settings Wolfram Sang
2011-12-09 19:13 ` Alan Cox
2011-12-09 17:07 ` [PATCH RESEND 7/8] serial: 8250: add Exar 16V2750 support Wolfram Sang
2011-12-09 17:07 ` [PATCH RESEND 8/8] serial: 8250: fix comment about accessing EMSR Wolfram Sang
2011-12-12 14:42 ` [PATCH RESEND 0/8] serial: 8250: support hw-based RS485 direction control Claudio Scordino
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