[PATCH AUTOSEL 4.14 212/371] serial: stm32: fix rx error handling

[PATCH AUTOSEL 4.14 212/371] serial: stm32: fix rx error handling

[Sasha Levin]

From: Erwan Le Ray <erwan.leray@st.com>

[ Upstream commit 4f01d833fdcdd6f9b85d9e5d5d7568eb683626a7 ]

- Fixes parity and framing error bit by clearing parity and framing error
  flag. The current implementation doesn't clear the error bits when an
  error is detected.
- Fixes the incorrect name of framing error clearing flag in header file.
- Fixes misalignement between data frame and errors status. The status
  read for "n" frame was the status of "n+1" frame".
- Fixes break detection was not triggered by the expected register.

Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/stm32-usart.c | 54 +++++++++++++++++++++-----------
 drivers/tty/serial/stm32-usart.h | 10 ++----
 2 files changed, 37 insertions(+), 27 deletions(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 03a583264d9e..c43590077372 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -118,35 +118,51 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded)
 
 	while (stm32_pending_rx(port, &sr, &stm32_port->last_res, threaded)) {
 		sr |= USART_SR_DUMMY_RX;
-		c = stm32_get_char(port, &sr, &stm32_port->last_res);
 		flag = TTY_NORMAL;
-		port->icount.rx++;
 
+		/*
+		 * Status bits has to be cleared before reading the RDR:
+		 * In FIFO mode, reading the RDR will pop the next data
+		 * (if any) along with its status bits into the SR.
+		 * Not doing so leads to misalignement between RDR and SR,
+		 * and clear status bits of the next rx data.
+		 *
+		 * Clear errors flags for stm32f7 and stm32h7 compatible
+		 * devices. On stm32f4 compatible devices, the error bit is
+		 * cleared by the sequence [read SR - read DR].
+		 */
+		if ((sr & USART_SR_ERR_MASK) && ofs->icr != UNDEF_REG)
+			stm32_clr_bits(port, ofs->icr, USART_ICR_ORECF |
+				       USART_ICR_PECF | USART_ICR_FECF);
+
+		c = stm32_get_char(port, &sr, &stm32_port->last_res);
+		port->icount.rx++;
 		if (sr & USART_SR_ERR_MASK) {
-			if (sr & USART_SR_LBD) {
-				port->icount.brk++;
-				if (uart_handle_break(port))
-					continue;
-			} else if (sr & USART_SR_ORE) {
-				if (ofs->icr != UNDEF_REG)
-					writel_relaxed(USART_ICR_ORECF,
-						       port->membase +
-						       ofs->icr);
+			if (sr & USART_SR_ORE) {
 				port->icount.overrun++;
 			} else if (sr & USART_SR_PE) {
 				port->icount.parity++;
 			} else if (sr & USART_SR_FE) {
-				port->icount.frame++;
+				/* Break detection if character is null */
+				if (!c) {
+					port->icount.brk++;
+					if (uart_handle_break(port))
+						continue;
+				} else {
+					port->icount.frame++;
+				}
 			}
 
 			sr &= port->read_status_mask;
 
-			if (sr & USART_SR_LBD)
-				flag = TTY_BREAK;
-			else if (sr & USART_SR_PE)
+			if (sr & USART_SR_PE) {
 				flag = TTY_PARITY;
-			else if (sr & USART_SR_FE)
-				flag = TTY_FRAME;
+			} else if (sr & USART_SR_FE) {
+				if (!c)
+					flag = TTY_BREAK;
+				else
+					flag = TTY_FRAME;
+			}
 		}
 
 		if (uart_handle_sysrq_char(port, c))
@@ -569,14 +585,14 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (termios->c_iflag & INPCK)
 		port->read_status_mask |= USART_SR_PE | USART_SR_FE;
 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
-		port->read_status_mask |= USART_SR_LBD;
+		port->read_status_mask |= USART_SR_FE;
 
 	/* Characters to ignore */
 	port->ignore_status_mask = 0;
 	if (termios->c_iflag & IGNPAR)
 		port->ignore_status_mask = USART_SR_PE | USART_SR_FE;
 	if (termios->c_iflag & IGNBRK) {
-		port->ignore_status_mask |= USART_SR_LBD;
+		port->ignore_status_mask |= USART_SR_FE;
 		/*
 		 * If we're ignoring parity and break indicators,
 		 * ignore overruns too (for real raw support).
diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h
index ffc0c5285e51..9d087881913a 100644
--- a/drivers/tty/serial/stm32-usart.h
+++ b/drivers/tty/serial/stm32-usart.h
@@ -108,7 +108,6 @@ struct stm32_usart_info stm32h7_info = {
 #define USART_SR_RXNE		BIT(5)
 #define USART_SR_TC		BIT(6)
 #define USART_SR_TXE		BIT(7)
-#define USART_SR_LBD		BIT(8)
 #define USART_SR_CTSIF		BIT(9)
 #define USART_SR_CTS		BIT(10)		/* F7 */
 #define USART_SR_RTOF		BIT(11)		/* F7 */
@@ -120,8 +119,7 @@ struct stm32_usart_info stm32h7_info = {
 #define USART_SR_SBKF		BIT(18)		/* F7 */
 #define USART_SR_WUF		BIT(20)		/* H7 */
 #define USART_SR_TEACK		BIT(21)		/* F7 */
-#define USART_SR_ERR_MASK	(USART_SR_LBD | USART_SR_ORE | \
-				 USART_SR_FE | USART_SR_PE)
+#define USART_SR_ERR_MASK	(USART_SR_ORE | USART_SR_FE | USART_SR_PE)
 /* Dummy bits */
 #define USART_SR_DUMMY_RX	BIT(16)
 
@@ -166,8 +164,6 @@ struct stm32_usart_info stm32h7_info = {
 /* USART_CR2 */
 #define USART_CR2_ADD_MASK	GENMASK(3, 0)	/* F4 */
 #define USART_CR2_ADDM7		BIT(4)		/* F7 */
-#define USART_CR2_LBDL		BIT(5)
-#define USART_CR2_LBDIE		BIT(6)
 #define USART_CR2_LBCL		BIT(8)
 #define USART_CR2_CPHA		BIT(9)
 #define USART_CR2_CPOL		BIT(10)
@@ -224,12 +220,10 @@ struct stm32_usart_info stm32h7_info = {
 
 /* USART_ICR */
 #define USART_ICR_PECF		BIT(0)		/* F7 */
-#define USART_ICR_FFECF		BIT(1)		/* F7 */
-#define USART_ICR_NCF		BIT(2)		/* F7 */
+#define USART_ICR_FECF		BIT(1)		/* F7 */
 #define USART_ICR_ORECF		BIT(3)		/* F7 */
 #define USART_ICR_IDLECF	BIT(4)		/* F7 */
 #define USART_ICR_TCCF		BIT(6)		/* F7 */
-#define USART_ICR_LBDCF		BIT(8)		/* F7 */
 #define USART_ICR_CTSCF		BIT(9)		/* F7 */
 #define USART_ICR_RTOCF		BIT(11)		/* F7 */
 #define USART_ICR_EOBCF		BIT(12)		/* F7 */
-- 
2.20.1

[PATCH AUTOSEL 4.14 213/371] serial: stm32: fix transmit_chars when tx is stopped

[Sasha Levin]

From: Erwan Le Ray <erwan.leray@st.com>

[ Upstream commit b83b957c91f68e53f0dc596e129e8305761f2a32 ]

Disables the tx irq  when the transmission is ended and updates stop_tx
conditions for code cleanup.

Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/stm32-usart.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index c43590077372..a1e31913bcf9 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -310,13 +310,8 @@ static void stm32_transmit_chars(struct uart_port *port)
 		return;
 	}
 
-	if (uart_tx_stopped(port)) {
-		stm32_stop_tx(port);
-		return;
-	}
-
-	if (uart_circ_empty(xmit)) {
-		stm32_stop_tx(port);
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		stm32_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
 		return;
 	}
 
@@ -329,7 +324,7 @@ static void stm32_transmit_chars(struct uart_port *port)
 		uart_write_wakeup(port);
 
 	if (uart_circ_empty(xmit))
-		stm32_stop_tx(port);
+		stm32_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
 }
 
 static irqreturn_t stm32_interrupt(int irq, void *ptr)
-- 
2.20.1

[PATCH AUTOSEL 4.14 214/371] serial: stm32: Add support of TC bit status check

[Sasha Levin]

From: Erwan Le Ray <erwan.leray@st.com>

[ Upstream commit 64c32eab660386f9904bb295a104c9c425e9f8b2 ]

Adds a check on the Transmission Complete bit status before closing the
com port. Prevents the port closure before the end of the transmission.
TC poll loop is moved from stm32_tx_dma_complete to stm32_shutdown
routine, in order to check TC before shutdown in both dma and
PIO tx modes.
TC clear is added in stm32_transmit_char routine, in order to be cleared
before transmitting in both dma and PIO tx modes.

Fixes: 3489187204eb ("serial: stm32: adding dma support")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/stm32-usart.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index a1e31913bcf9..2384f786b76d 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -180,21 +180,6 @@ static void stm32_tx_dma_complete(void *arg)
 	struct uart_port *port = arg;
 	struct stm32_port *stm32port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
-	unsigned int isr;
-	int ret;
-
-	ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
-						isr,
-						(isr & USART_SR_TC),
-						10, 100000);
-
-	if (ret)
-		dev_err(port->dev, "terminal count not set\n");
-
-	if (ofs->icr == UNDEF_REG)
-		stm32_clr_bits(port, ofs->isr, USART_SR_TC);
-	else
-		stm32_set_bits(port, ofs->icr, USART_CR_TC);
 
 	stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 	stm32port->tx_dma_busy = false;
@@ -286,7 +271,6 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 	/* Issue pending DMA TX requests */
 	dma_async_issue_pending(stm32port->tx_ch);
 
-	stm32_clr_bits(port, ofs->isr, USART_SR_TC);
 	stm32_set_bits(port, ofs->cr3, USART_CR3_DMAT);
 
 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
@@ -315,6 +299,11 @@ static void stm32_transmit_chars(struct uart_port *port)
 		return;
 	}
 
+	if (ofs->icr == UNDEF_REG)
+		stm32_clr_bits(port, ofs->isr, USART_SR_TC);
+	else
+		stm32_set_bits(port, ofs->icr, USART_ICR_TCCF);
+
 	if (stm32_port->tx_ch)
 		stm32_transmit_chars_dma(port);
 	else
@@ -491,12 +480,21 @@ static void stm32_shutdown(struct uart_port *port)
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
-	u32 val;
+	u32 val, isr;
+	int ret;
 
 	val = USART_CR1_TXEIE | USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
 	val |= BIT(cfg->uart_enable_bit);
 	if (stm32_port->fifoen)
 		val |= USART_CR1_FIFOEN;
+
+	ret = readl_relaxed_poll_timeout(port->membase + ofs->isr,
+					 isr, (isr & USART_SR_TC),
+					 10, 100000);
+
+	if (ret)
+		dev_err(port->dev, "transmission complete not set\n");
+
 	stm32_clr_bits(port, ofs->cr1, val);
 
 	dev_pm_clear_wake_irq(port->dev);
-- 
2.20.1

[PATCH AUTOSEL 4.14 215/371] serial: stm32: fix wakeup source initialization

[Sasha Levin]

From: Erwan Le Ray <erwan.leray@st.com>

[ Upstream commit 5297f274e8b61ceb9676cba6649d3de9d03387ad ]

Fixes dedicated_irq_wakeup issue and deactivated uart as wakeup source by
default.

Fixes: 270e5a74fe4c ("serial: stm32: add wakeup mechanism")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/stm32-usart.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 2384f786b76d..f8f3f8fafd9f 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -447,7 +447,6 @@ static int stm32_startup(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
 	const char *name = to_platform_device(port->dev)->name;
 	u32 val;
 	int ret;
@@ -458,15 +457,6 @@ static int stm32_startup(struct uart_port *port)
 	if (ret)
 		return ret;
 
-	if (cfg->has_wakeup && stm32_port->wakeirq >= 0) {
-		ret = dev_pm_set_dedicated_wake_irq(port->dev,
-						    stm32_port->wakeirq);
-		if (ret) {
-			free_irq(port->irq, port);
-			return ret;
-		}
-	}
-
 	val = USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
 	if (stm32_port->fifoen)
 		val |= USART_CR1_FIFOEN;
@@ -497,7 +487,6 @@ static void stm32_shutdown(struct uart_port *port)
 
 	stm32_clr_bits(port, ofs->cr1, val);
 
-	dev_pm_clear_wake_irq(port->dev);
 	free_irq(port->irq, port);
 }
 
@@ -904,11 +893,18 @@ static int stm32_serial_probe(struct platform_device *pdev)
 		ret = device_init_wakeup(&pdev->dev, true);
 		if (ret)
 			goto err_uninit;
+
+		ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
+						    stm32port->wakeirq);
+		if (ret)
+			goto err_nowup;
+
+		device_set_wakeup_enable(&pdev->dev, false);
 	}
 
 	ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port);
 	if (ret)
-		goto err_nowup;
+		goto err_wirq;
 
 	ret = stm32_of_dma_rx_probe(stm32port, pdev);
 	if (ret)
@@ -922,6 +918,10 @@ static int stm32_serial_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_wirq:
+	if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0)
+		dev_pm_clear_wake_irq(&pdev->dev);
+
 err_nowup:
 	if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0)
 		device_init_wakeup(&pdev->dev, false);
@@ -959,8 +959,10 @@ static int stm32_serial_remove(struct platform_device *pdev)
 				  TX_BUF_L, stm32_port->tx_buf,
 				  stm32_port->tx_dma_buf);
 
-	if (cfg->has_wakeup && stm32_port->wakeirq >= 0)
+	if (cfg->has_wakeup && stm32_port->wakeirq >= 0) {
+		dev_pm_clear_wake_irq(&pdev->dev);
 		device_init_wakeup(&pdev->dev, false);
+	}
 
 	clk_disable_unprepare(stm32_port->clk);
 
-- 
2.20.1

[PATCH AUTOSEL 4.14 288/371] tty: serial: fsl_lpuart: Use appropriate lpuart32_* I/O funcs

[Sasha Levin]

From: Andrey Smirnov <andrew.smirnov@gmail.com>

[ Upstream commit 1da17d7cf8e2c4b60163d54300f72c02f510327c ]

When dealing with 32-bit variant of LPUART IP block appropriate I/O
helpers have to be used to properly deal with endianness
differences. Change all of the offending code to do that.

Fixes: a5fa2660d787 ("tty/serial/fsl_lpuart: Add CONSOLE_POLL support
for lpuart32.")
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Cory Tusar <cory.tusar@zii.aero>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-imx@nxp.com
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20190729195226.8862-14-andrew.smirnov@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/fsl_lpuart.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index fb2dcb3f8591..16422987ab0f 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -532,26 +532,26 @@ static int lpuart32_poll_init(struct uart_port *port)
 	spin_lock_irqsave(&sport->port.lock, flags);
 
 	/* Disable Rx & Tx */
-	writel(0, sport->port.membase + UARTCTRL);
+	lpuart32_write(&sport->port, UARTCTRL, 0);
 
-	temp = readl(sport->port.membase + UARTFIFO);
+	temp = lpuart32_read(&sport->port, UARTFIFO);
 
 	/* Enable Rx and Tx FIFO */
-	writel(temp | UARTFIFO_RXFE | UARTFIFO_TXFE,
-		   sport->port.membase + UARTFIFO);
+	lpuart32_write(&sport->port, UARTFIFO,
+		       temp | UARTFIFO_RXFE | UARTFIFO_TXFE);
 
 	/* flush Tx and Rx FIFO */
-	writel(UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH,
-			sport->port.membase + UARTFIFO);
+	lpuart32_write(&sport->port, UARTFIFO,
+		       UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH);
 
 	/* explicitly clear RDRF */
-	if (readl(sport->port.membase + UARTSTAT) & UARTSTAT_RDRF) {
-		readl(sport->port.membase + UARTDATA);
-		writel(UARTFIFO_RXUF, sport->port.membase + UARTFIFO);
+	if (lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_RDRF) {
+		lpuart32_read(&sport->port, UARTDATA);
+		lpuart32_write(&sport->port, UARTFIFO, UARTFIFO_RXUF);
 	}
 
 	/* Enable Rx and Tx */
-	writel(UARTCTRL_RE | UARTCTRL_TE, sport->port.membase + UARTCTRL);
+	lpuart32_write(&sport->port, UARTCTRL, UARTCTRL_RE | UARTCTRL_TE);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 
 	return 0;
@@ -559,18 +559,18 @@ static int lpuart32_poll_init(struct uart_port *port)
 
 static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)
 {
-	while (!(readl(port->membase + UARTSTAT) & UARTSTAT_TDRE))
+	while (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE))
 		barrier();
 
-	writel(c, port->membase + UARTDATA);
+	lpuart32_write(port, UARTDATA, c);
 }
 
 static int lpuart32_poll_get_char(struct uart_port *port)
 {
-	if (!(readl(port->membase + UARTSTAT) & UARTSTAT_RDRF))
+	if (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_RDRF))
 		return NO_POLL_CHAR;
 
-	return readl(port->membase + UARTDATA);
+	return lpuart32_read(port, UARTDATA);
 }
 #endif
 
-- 
2.20.1

[PATCH AUTOSEL 4.14 351/371] tty: serial: imx: use the sg count from dma_map_sg

[Sasha Levin]

From: Peng Fan <peng.fan@nxp.com>

[ Upstream commit 596fd8dffb745afcebc0ec6968e17fe29f02044c ]

The dmaengine_prep_slave_sg needs to use sg count returned
by dma_map_sg, not use sport->dma_tx_nents, because the return
value of dma_map_sg is not always same with "nents".

Fixes: b4cdc8f61beb ("serial: imx: add DMA support for imx6q")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1573108875-26530-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/imx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index aae68230fb7b..a81a5be0cf7a 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -542,7 +542,7 @@ static void imx_dma_tx(struct imx_port *sport)
 		dev_err(dev, "DMA mapping error for TX.\n");
 		return;
 	}
-	desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
+	desc = dmaengine_prep_slave_sg(chan, sgl, ret,
 					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 	if (!desc) {
 		dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
-- 
2.20.1

[PATCH AUTOSEL 4.14 352/371] tty: serial: pch_uart: correct usage of dma_unmap_sg

[Sasha Levin]

From: Peng Fan <peng.fan@nxp.com>

[ Upstream commit 74887542fdcc92ad06a48c0cca17cdf09fc8aa00 ]

Per Documentation/DMA-API-HOWTO.txt,
To unmap a scatterlist, just call:
	dma_unmap_sg(dev, sglist, nents, direction);

.. note::

	The 'nents' argument to the dma_unmap_sg call must be
	the _same_ one you passed into the dma_map_sg call,
	it should _NOT_ be the 'count' value _returned_ from the
	dma_map_sg call.

However in the driver, priv->nent is directly assigned with value
returned from dma_map_sg, and dma_unmap_sg use priv->nent for unmap,
this breaks the API usage.

So introduce a new entry orig_nent to remember 'nents'.

Fixes: da3564ee027e ("pch_uart: add multi-scatter processing")
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1573623259-6339-1-git-send-email-peng.fan@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/pch_uart.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index d9123f995705..15ddcbd1f9d2 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -247,6 +247,7 @@ struct eg20t_port {
 	struct dma_chan			*chan_rx;
 	struct scatterlist		*sg_tx_p;
 	int				nent;
+	int				orig_nent;
 	struct scatterlist		sg_rx;
 	int				tx_dma_use;
 	void				*rx_buf_virt;
@@ -801,9 +802,10 @@ static void pch_dma_tx_complete(void *arg)
 	}
 	xmit->tail &= UART_XMIT_SIZE - 1;
 	async_tx_ack(priv->desc_tx);
-	dma_unmap_sg(port->dev, sg, priv->nent, DMA_TO_DEVICE);
+	dma_unmap_sg(port->dev, sg, priv->orig_nent, DMA_TO_DEVICE);
 	priv->tx_dma_use = 0;
 	priv->nent = 0;
+	priv->orig_nent = 0;
 	kfree(priv->sg_tx_p);
 	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
 }
@@ -1027,6 +1029,7 @@ static unsigned int dma_handle_tx(struct eg20t_port *priv)
 		dev_err(priv->port.dev, "%s:dma_map_sg Failed\n", __func__);
 		return 0;
 	}
+	priv->orig_nent = num;
 	priv->nent = nent;
 
 	for (i = 0; i < nent; i++, sg++) {
-- 
2.20.1

[PATCH AUTOSEL 4.14 371/371] serial: stm32: fix clearing interrupt error flags

[Sasha Levin]

From: Fabrice Gasnier <fabrice.gasnier@st.com>

[ Upstream commit 1250ed7114a977cdc2a67a0c09d6cdda63970eb9 ]

The interrupt clear flag register is a "write 1 to clear" register.
So, only writing ones allows to clear flags:
- Replace buggy stm32_clr_bits() by a simple write to clear error flags
- Replace useless read/modify/write stm32_set_bits() routine by a
  simple write to clear TC (transfer complete) flag.

Fixes: 4f01d833fdcd ("serial: stm32: fix rx error handling")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1574323849-1909-1-git-send-email-fabrice.gasnier@st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/stm32-usart.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index f8f3f8fafd9f..1e854e1851fb 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -132,8 +132,8 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded)
 		 * cleared by the sequence [read SR - read DR].
 		 */
 		if ((sr & USART_SR_ERR_MASK) && ofs->icr != UNDEF_REG)
-			stm32_clr_bits(port, ofs->icr, USART_ICR_ORECF |
-				       USART_ICR_PECF | USART_ICR_FECF);
+			writel_relaxed(sr & USART_SR_ERR_MASK,
+				       port->membase + ofs->icr);
 
 		c = stm32_get_char(port, &sr, &stm32_port->last_res);
 		port->icount.rx++;
@@ -302,7 +302,7 @@ static void stm32_transmit_chars(struct uart_port *port)
 	if (ofs->icr == UNDEF_REG)
 		stm32_clr_bits(port, ofs->isr, USART_SR_TC);
 	else
-		stm32_set_bits(port, ofs->icr, USART_ICR_TCCF);
+		writel_relaxed(USART_ICR_TCCF, port->membase + ofs->icr);
 
 	if (stm32_port->tx_ch)
 		stm32_transmit_chars_dma(port);
-- 
2.20.1