1 files changed, 42 insertions, 17 deletions

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 10db3e54ac9e..3a7ad301ee8c 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -609,7 +609,7 @@ static void imx_uart_dma_tx(struct imx_port *sport)
 
 	sport->tx_bytes = uart_circ_chars_pending(xmit);
 
-	if (xmit->tail < xmit->head) {
+	if (xmit->tail < xmit->head || xmit->head == 0) {
 		sport->dma_tx_nents = 1;
 		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
 	} else {
@@ -625,7 +625,7 @@ static void imx_uart_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,
@@ -706,22 +706,33 @@ static void imx_uart_start_tx(struct uart_port *port)
 	}
 }
 
-static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
+static irqreturn_t __imx_uart_rtsint(int irq, void *dev_id)
 {
 	struct imx_port *sport = dev_id;
 	u32 usr1;
 
-	spin_lock(&sport->port.lock);
-
 	imx_uart_writel(sport, USR1_RTSD, USR1);
 	usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
 	uart_handle_cts_change(&sport->port, !!usr1);
 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 
-	spin_unlock(&sport->port.lock);
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+	irqreturn_t ret;
+
+	spin_lock(&sport->port.lock);
+
+	ret = __imx_uart_rtsint(irq, dev_id);
+
+	spin_unlock(&sport->port.lock);
+
+	return ret;
+}
+
 static irqreturn_t imx_uart_txint(int irq, void *dev_id)
 {
 	struct imx_port *sport = dev_id;
@@ -732,14 +743,12 @@ static irqreturn_t imx_uart_txint(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
+static irqreturn_t __imx_uart_rxint(int irq, void *dev_id)
 {
 	struct imx_port *sport = dev_id;
 	unsigned int rx, flg, ignored = 0;
 	struct tty_port *port = &sport->port.state->port;
 
-	spin_lock(&sport->port.lock);
-
 	while (imx_uart_readl(sport, USR2) & USR2_RDR) {
 		u32 usr2;
 
@@ -798,11 +807,25 @@ static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
 	}
 
 out:
-	spin_unlock(&sport->port.lock);
 	tty_flip_buffer_push(port);
+
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
+{
+	struct imx_port *sport = dev_id;
+	irqreturn_t ret;
+
+	spin_lock(&sport->port.lock);
+
+	ret = __imx_uart_rxint(irq, dev_id);
+
+	spin_unlock(&sport->port.lock);
+
+	return ret;
+}
+
 static void imx_uart_clear_rx_errors(struct imx_port *sport);
 
 /*
@@ -861,6 +884,8 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id)
 	unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
 	irqreturn_t ret = IRQ_NONE;
 
+	spin_lock(&sport->port.lock);
+
 	usr1 = imx_uart_readl(sport, USR1);
 	usr2 = imx_uart_readl(sport, USR2);
 	ucr1 = imx_uart_readl(sport, UCR1);
@@ -894,27 +919,25 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id)
 		usr2 &= ~USR2_ORE;
 
 	if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
-		imx_uart_rxint(irq, dev_id);
+		__imx_uart_rxint(irq, dev_id);
 		ret = IRQ_HANDLED;
 	}
 
 	if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
-		imx_uart_txint(irq, dev_id);
+		imx_uart_transmit_buffer(sport);
 		ret = IRQ_HANDLED;
 	}
 
 	if (usr1 & USR1_DTRD) {
 		imx_uart_writel(sport, USR1_DTRD, USR1);
 
-		spin_lock(&sport->port.lock);
 		imx_uart_mctrl_check(sport);
-		spin_unlock(&sport->port.lock);
 
 		ret = IRQ_HANDLED;
 	}
 
 	if (usr1 & USR1_RTSD) {
-		imx_uart_rtsint(irq, dev_id);
+		__imx_uart_rtsint(irq, dev_id);
 		ret = IRQ_HANDLED;
 	}
 
@@ -929,6 +952,8 @@ static irqreturn_t imx_uart_int(int irq, void *dev_id)
 		ret = IRQ_HANDLED;
 	}
 
+	spin_unlock(&sport->port.lock);
+
 	return ret;
 }
 
@@ -2221,8 +2246,8 @@ static int imx_uart_probe(struct platform_device *pdev)
 		return PTR_ERR(base);
 
 	rxirq = platform_get_irq(pdev, 0);
-	txirq = platform_get_irq(pdev, 1);
-	rtsirq = platform_get_irq(pdev, 2);
+	txirq = platform_get_irq_optional(pdev, 1);
+	rtsirq = platform_get_irq_optional(pdev, 2);
 
 	sport->port.dev = &pdev->dev;
 	sport->port.mapbase = res->start;