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From: Erwan Le Ray <erwan.leray@foss.st.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: <linux-serial@vger.kernel.org>,
	<linux-stm32@st-md-mailman.stormreply.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	Erwan Le Ray <erwan.leray@foss.st.com>,
	Fabrice Gasnier <fabrice.gasnier@foss.st.com>,
	Valentin Caron <valentin.caron@foss.st.com>
Subject: [PATCH 13/13] serial: stm32: add support for "flush_buffer" ops
Date: Fri, 19 Feb 2021 18:47:36 +0100	[thread overview]
Message-ID: <20210219174736.1022-14-erwan.leray@foss.st.com> (raw)
In-Reply-To: <20210219174736.1022-1-erwan.leray@foss.st.com>

Add the support for "flush_buffer" ops in order to flush any write buffers,
reset any DMA state and stop any ongoing DMA transfers when the
port->state->xmit circular buffer is cleared.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 114408f3892a..92836068e5ec 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -597,6 +597,19 @@ static void stm32_usart_start_tx(struct uart_port *port)
 	stm32_usart_transmit_chars(port);
 }
 
+/* Flush the transmit buffer. */
+static void stm32_usart_flush_buffer(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (stm32_port->tx_ch) {
+		dmaengine_terminate_async(stm32_port->tx_ch);
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+		stm32_port->tx_dma_busy = false;
+	}
+}
+
 /* Throttle the remote when input buffer is about to overflow. */
 static void stm32_usart_throttle(struct uart_port *port)
 {
@@ -992,6 +1005,7 @@ static const struct uart_ops stm32_uart_ops = {
 	.break_ctl	= stm32_usart_break_ctl,
 	.startup	= stm32_usart_startup,
 	.shutdown	= stm32_usart_shutdown,
+	.flush_buffer	= stm32_usart_flush_buffer,
 	.set_termios	= stm32_usart_set_termios,
 	.pm		= stm32_usart_pm,
 	.type		= stm32_usart_type,
-- 
2.17.1


WARNING: multiple messages have this Message-ID (diff)
From: Erwan Le Ray <erwan.leray@foss.st.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Valentin Caron <valentin.caron@foss.st.com>,
	Erwan Le Ray <erwan.leray@foss.st.com>,
	linux-kernel@vger.kernel.org,
	Fabrice Gasnier <fabrice.gasnier@foss.st.com>,
	linux-serial@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 13/13] serial: stm32: add support for "flush_buffer" ops
Date: Fri, 19 Feb 2021 18:47:36 +0100	[thread overview]
Message-ID: <20210219174736.1022-14-erwan.leray@foss.st.com> (raw)
In-Reply-To: <20210219174736.1022-1-erwan.leray@foss.st.com>

Add the support for "flush_buffer" ops in order to flush any write buffers,
reset any DMA state and stop any ongoing DMA transfers when the
port->state->xmit circular buffer is cleared.

Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 114408f3892a..92836068e5ec 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -597,6 +597,19 @@ static void stm32_usart_start_tx(struct uart_port *port)
 	stm32_usart_transmit_chars(port);
 }
 
+/* Flush the transmit buffer. */
+static void stm32_usart_flush_buffer(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (stm32_port->tx_ch) {
+		dmaengine_terminate_async(stm32_port->tx_ch);
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
+		stm32_port->tx_dma_busy = false;
+	}
+}
+
 /* Throttle the remote when input buffer is about to overflow. */
 static void stm32_usart_throttle(struct uart_port *port)
 {
@@ -992,6 +1005,7 @@ static const struct uart_ops stm32_uart_ops = {
 	.break_ctl	= stm32_usart_break_ctl,
 	.startup	= stm32_usart_startup,
 	.shutdown	= stm32_usart_shutdown,
+	.flush_buffer	= stm32_usart_flush_buffer,
 	.set_termios	= stm32_usart_set_termios,
 	.pm		= stm32_usart_pm,
 	.type		= stm32_usart_type,
-- 
2.17.1


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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2021-02-19 17:52 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-19 17:47 [PATCH 00/13] stm32 usart various fixes Erwan Le Ray
2021-02-19 17:47 ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 01/13] serial: stm32: fix probe and remove order for dma Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 02/13] serial: stm32: fix startup by enabling usart for reception Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 03/13] serial: stm32: fix incorrect characters on console Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 04/13] serial: stm32: fix TX and RX FIFO thresholds Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 05/13] serial: stm32: fix a deadlock condition with wakeup event Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 06/13] serial: stm32: fix wake-up flag handling Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 07/13] serial: stm32: fix a deadlock in set_termios Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 08/13] serial: stm32: fix tx dma completion, release channel Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 09/13] serial: stm32: call stm32_transmit_chars locked Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 10/13] serial: stm32: fix FIFO flush in startup and set_termios Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 11/13] serial: stm32: add FIFO flush when port is closed Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` [PATCH 12/13] serial: stm32: fix tx_empty condition Erwan Le Ray
2021-02-19 17:47   ` Erwan Le Ray
2021-02-19 17:47 ` Erwan Le Ray [this message]
2021-02-19 17:47   ` [PATCH 13/13] serial: stm32: add support for "flush_buffer" ops Erwan Le Ray
2021-03-03 19:31 ` [PATCH 00/13] stm32 usart various fixes Greg Kroah-Hartman
2021-03-03 19:31   ` Greg Kroah-Hartman

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