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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 v2 12/13] serial: stm32: fix tx_empty condition
Date: Thu, 4 Mar 2021 17:23:07 +0100	[thread overview]
Message-ID: <20210304162308.8984-13-erwan.leray@foss.st.com> (raw)
In-Reply-To: <20210304162308.8984-1-erwan.leray@foss.st.com>

In "tx_empty", we should poll TC bit in both DMA and PIO modes (instead of
TXE) to check transmission data register has been transmitted independently
of the FIFO mode. TC indicates that both transmit register and shift
register are empty. When shift register is empty, tx_empty should return
TIOCSER_TEMT instead of TC value.

Cleans the USART_CR_TC TCCF register define (transmission complete clear
flag) as it is duplicate of USART_ICR_TCCF.

Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver")
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 d205fce1950a..99dfa884cbef 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -515,7 +515,10 @@ static unsigned int stm32_usart_tx_empty(struct uart_port *port)
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
-	return readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE;
+	if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC)
+		return TIOCSER_TEMT;
+
+	return 0;
 }
 
 static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl)
diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h
index cb4f327c46db..94b568aa46bb 100644
--- a/drivers/tty/serial/stm32-usart.h
+++ b/drivers/tty/serial/stm32-usart.h
@@ -127,9 +127,6 @@ struct stm32_usart_info stm32h7_info = {
 /* Dummy bits */
 #define USART_SR_DUMMY_RX	BIT(16)
 
-/* USART_ICR (F7) */
-#define USART_CR_TC		BIT(6)
-
 /* USART_DR */
 #define USART_DR_MASK		GENMASK(8, 0)
 
-- 
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: <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 v2 12/13] serial: stm32: fix tx_empty condition
Date: Thu, 4 Mar 2021 17:23:07 +0100	[thread overview]
Message-ID: <20210304162308.8984-13-erwan.leray@foss.st.com> (raw)
In-Reply-To: <20210304162308.8984-1-erwan.leray@foss.st.com>

In "tx_empty", we should poll TC bit in both DMA and PIO modes (instead of
TXE) to check transmission data register has been transmitted independently
of the FIFO mode. TC indicates that both transmit register and shift
register are empty. When shift register is empty, tx_empty should return
TIOCSER_TEMT instead of TC value.

Cleans the USART_CR_TC TCCF register define (transmission complete clear
flag) as it is duplicate of USART_ICR_TCCF.

Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver")
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 d205fce1950a..99dfa884cbef 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -515,7 +515,10 @@ static unsigned int stm32_usart_tx_empty(struct uart_port *port)
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
-	return readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE;
+	if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC)
+		return TIOCSER_TEMT;
+
+	return 0;
 }
 
 static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl)
diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h
index cb4f327c46db..94b568aa46bb 100644
--- a/drivers/tty/serial/stm32-usart.h
+++ b/drivers/tty/serial/stm32-usart.h
@@ -127,9 +127,6 @@ struct stm32_usart_info stm32h7_info = {
 /* Dummy bits */
 #define USART_SR_DUMMY_RX	BIT(16)
 
-/* USART_ICR (F7) */
-#define USART_CR_TC		BIT(6)
-
 /* USART_DR */
 #define USART_DR_MASK		GENMASK(8, 0)
 
-- 
2.17.1


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  parent reply	other threads:[~2021-03-04 16:25 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-04 16:22 [PATCH v2 00/13] stm32 usart various fixes Erwan Le Ray
2021-03-04 16:22 ` Erwan Le Ray
2021-03-04 16:22 ` [PATCH v2 01/13] serial: stm32: fix probe and remove order for dma Erwan Le Ray
2021-03-04 16:22   ` Erwan Le Ray
2021-03-04 16:22 ` [PATCH v2 02/13] serial: stm32: fix startup by enabling usart for reception Erwan Le Ray
2021-03-04 16:22   ` Erwan Le Ray
2021-03-04 16:22 ` [PATCH v2 03/13] serial: stm32: fix incorrect characters on console Erwan Le Ray
2021-03-04 16:22   ` Erwan Le Ray
2021-03-04 16:22 ` [PATCH v2 04/13] serial: stm32: fix TX and RX FIFO thresholds Erwan Le Ray
2021-03-04 16:22   ` Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 05/13] serial: stm32: fix a deadlock condition with wakeup event Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 06/13] serial: stm32: fix wake-up flag handling Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 07/13] serial: stm32: fix a deadlock in set_termios Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 08/13] serial: stm32: fix tx dma completion, release channel Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 09/13] serial: stm32: call stm32_transmit_chars locked Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 10/13] serial: stm32: fix FIFO flush in startup and set_termios Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 11/13] serial: stm32: add FIFO flush when port is closed Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray
2021-03-04 16:23 ` Erwan Le Ray [this message]
2021-03-04 16:23   ` [PATCH v2 12/13] serial: stm32: fix tx_empty condition Erwan Le Ray
2021-03-04 16:23 ` [PATCH v2 13/13] serial: stm32: add support for "flush_buffer" ops Erwan Le Ray
2021-03-04 16:23   ` Erwan Le Ray

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