1 files changed, 31 insertions, 56 deletions

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index dfdbcf092fac..409e91d6829a 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -596,8 +596,7 @@ static void stm32_usart_transmit_chars_pio(struct uart_port *port)
 		if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE))
 			break;
 		writel_relaxed(xmit->buf[xmit->tail], port->membase + ofs->tdr);
-		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-		port->icount.tx++;
+		uart_xmit_advance(port, 1);
 	}
 
 	/* rely on TXE irq (mask or unmask) for sending remaining data */
@@ -673,8 +672,8 @@ static void stm32_usart_transmit_chars_dma(struct uart_port *port)
 
 	stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAT);
 
-	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
-	port->icount.tx += count;
+	uart_xmit_advance(port, count);
+
 	return;
 
 fallback_err:
@@ -798,25 +797,11 @@ static irqreturn_t stm32_usart_interrupt(int irq, void *ptr)
 		spin_unlock(&port->lock);
 	}
 
-	if (stm32_usart_rx_dma_enabled(port))
-		return IRQ_WAKE_THREAD;
-	else
-		return IRQ_HANDLED;
-}
-
-static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr)
-{
-	struct uart_port *port = ptr;
-	struct tty_port *tport = &port->state->port;
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	unsigned int size;
-	unsigned long flags;
-
 	/* Receiver timeout irq for DMA RX */
-	if (!stm32_port->throttled) {
-		spin_lock_irqsave(&port->lock, flags);
+	if (stm32_usart_rx_dma_enabled(port) && !stm32_port->throttled) {
+		spin_lock(&port->lock);
 		size = stm32_usart_receive_chars(port, false);
-		uart_unlock_and_check_sysrq_irqrestore(port, flags);
+		uart_unlock_and_check_sysrq(port);
 		if (size)
 			tty_flip_buffer_push(tport);
 	}
@@ -1016,10 +1001,8 @@ static int stm32_usart_startup(struct uart_port *port)
 	u32 val;
 	int ret;
 
-	ret = request_threaded_irq(port->irq, stm32_usart_interrupt,
-				   stm32_usart_threaded_interrupt,
-				   IRQF_ONESHOT | IRQF_NO_SUSPEND,
-				   name, port);
+	ret = request_irq(port->irq, stm32_usart_interrupt,
+			  IRQF_NO_SUSPEND, name, port);
 	if (ret)
 		return ret;
 
@@ -1602,13 +1585,6 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port,
 	struct dma_slave_config config;
 	int ret;
 
-	/*
-	 * Using DMA and threaded handler for the console could lead to
-	 * deadlocks.
-	 */
-	if (uart_console(port))
-		return -ENODEV;
-
 	stm32port->rx_buf = dma_alloc_coherent(dev, RX_BUF_L,
 					       &stm32port->rx_dma_buf,
 					       GFP_KERNEL);
@@ -1681,22 +1657,10 @@ static int stm32_usart_serial_probe(struct platform_device *pdev)
 	if (!stm32port->info)
 		return -EINVAL;
 
-	ret = stm32_usart_init_port(stm32port, pdev);
-	if (ret)
-		return ret;
-
-	if (stm32port->wakeup_src) {
-		device_set_wakeup_capable(&pdev->dev, true);
-		ret = dev_pm_set_wake_irq(&pdev->dev, stm32port->port.irq);
-		if (ret)
-			goto err_deinit_port;
-	}
-
 	stm32port->rx_ch = dma_request_chan(&pdev->dev, "rx");
-	if (PTR_ERR(stm32port->rx_ch) == -EPROBE_DEFER) {
-		ret = -EPROBE_DEFER;
-		goto err_wakeirq;
-	}
+	if (PTR_ERR(stm32port->rx_ch) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
 	/* Fall back in interrupt mode for any non-deferral error */
 	if (IS_ERR(stm32port->rx_ch))
 		stm32port->rx_ch = NULL;
@@ -1710,6 +1674,17 @@ static int stm32_usart_serial_probe(struct platform_device *pdev)
 	if (IS_ERR(stm32port->tx_ch))
 		stm32port->tx_ch = NULL;
 
+	ret = stm32_usart_init_port(stm32port, pdev);
+	if (ret)
+		goto err_dma_tx;
+
+	if (stm32port->wakeup_src) {
+		device_set_wakeup_capable(&pdev->dev, true);
+		ret = dev_pm_set_wake_irq(&pdev->dev, stm32port->port.irq);
+		if (ret)
+			goto err_deinit_port;
+	}
+
 	if (stm32port->rx_ch && stm32_usart_of_dma_rx_probe(stm32port, pdev)) {
 		/* Fall back in interrupt mode */
 		dma_release_channel(stm32port->rx_ch);
@@ -1746,19 +1721,11 @@ err_port:
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
 
-	if (stm32port->tx_ch) {
+	if (stm32port->tx_ch)
 		stm32_usart_of_dma_tx_remove(stm32port, pdev);
-		dma_release_channel(stm32port->tx_ch);
-	}
-
 	if (stm32port->rx_ch)
 		stm32_usart_of_dma_rx_remove(stm32port, pdev);
 
-err_dma_rx:
-	if (stm32port->rx_ch)
-		dma_release_channel(stm32port->rx_ch);
-
-err_wakeirq:
 	if (stm32port->wakeup_src)
 		dev_pm_clear_wake_irq(&pdev->dev);
 
@@ -1768,6 +1735,14 @@ err_deinit_port:
 
 	stm32_usart_deinit_port(stm32port);
 
+err_dma_tx:
+	if (stm32port->tx_ch)
+		dma_release_channel(stm32port->tx_ch);
+
+err_dma_rx:
+	if (stm32port->rx_ch)
+		dma_release_channel(stm32port->rx_ch);
+
 	return ret;
 }