1 files changed, 48 insertions, 50 deletions

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index b1905a93fac9..bb8316587917 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -237,7 +237,8 @@ struct lpuart_port {
 	unsigned int		rxfifo_size;
 	bool			lpuart32;
 
-	bool			lpuart_dma_use;
+	bool			lpuart_dma_tx_use;
+	bool			lpuart_dma_rx_use;
 	struct dma_chan		*dma_tx_chan;
 	struct dma_chan		*dma_rx_chan;
 	struct dma_async_tx_descriptor  *dma_tx_desc;
@@ -568,7 +569,7 @@ static void lpuart_start_tx(struct uart_port *port)
 	temp = readb(port->membase + UARTCR2);
 	writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
 
-	if (sport->lpuart_dma_use) {
+	if (sport->lpuart_dma_tx_use) {
 		if (!uart_circ_empty(xmit) && !sport->dma_tx_in_progress)
 			lpuart_prepare_tx(sport);
 	} else {
@@ -760,14 +761,16 @@ static irqreturn_t lpuart_int(int irq, void *dev_id)
 	sts = readb(sport->port.membase + UARTSR1);
 
 	if (sts & UARTSR1_RDRF) {
-		if (sport->lpuart_dma_use)
+		if (timer_pending(&sport->lpuart_timer))
+			printk("sts is %02x\n", sts);
+		if (sport->lpuart_dma_rx_use)
 			lpuart_prepare_rx(sport);
 		else
 			lpuart_rxint(irq, dev_id);
 	}
 	if (sts & UARTSR1_TDRE &&
 		!(readb(sport->port.membase + UARTCR5) & UARTCR5_TDMAS)) {
-		if (sport->lpuart_dma_use)
+		if (sport->lpuart_dma_tx_use)
 			lpuart_pio_tx(sport);
 		else
 			lpuart_txint(irq, dev_id);
@@ -950,26 +953,17 @@ static int lpuart_dma_tx_request(struct uart_port *port)
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *tx_chan;
 	struct dma_slave_config dma_tx_sconfig;
 	dma_addr_t dma_bus;
 	unsigned char *dma_buf;
 	int ret;
 
-	tx_chan  = dma_request_slave_channel(sport->port.dev, "tx");
-
-	if (!tx_chan) {
-		dev_err(sport->port.dev, "Dma tx channel request failed!\n");
-		return -ENODEV;
-	}
-
-	dma_bus = dma_map_single(tx_chan->device->dev,
+	dma_bus = dma_map_single(sport->dma_tx_chan->device->dev,
 				sport->port.state->xmit.buf,
 				UART_XMIT_SIZE, DMA_TO_DEVICE);
 
-	if (dma_mapping_error(tx_chan->device->dev, dma_bus)) {
+	if (dma_mapping_error(sport->dma_tx_chan->device->dev, dma_bus)) {
 		dev_err(sport->port.dev, "dma_map_single tx failed\n");
-		dma_release_channel(tx_chan);
 		return -ENOMEM;
 	}
 
@@ -978,16 +972,14 @@ static int lpuart_dma_tx_request(struct uart_port *port)
 	dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	dma_tx_sconfig.dst_maxburst = sport->txfifo_size;
 	dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
-	ret = dmaengine_slave_config(tx_chan, &dma_tx_sconfig);
+	ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig);
 
 	if (ret < 0) {
 		dev_err(sport->port.dev,
 				"Dma slave config failed, err = %d\n", ret);
-		dma_release_channel(tx_chan);
 		return ret;
 	}
 
-	sport->dma_tx_chan = tx_chan;
 	sport->dma_tx_buf_virt = dma_buf;
 	sport->dma_tx_buf_bus = dma_bus;
 	sport->dma_tx_in_progress = 0;
@@ -999,34 +991,24 @@ static int lpuart_dma_rx_request(struct uart_port *port)
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *rx_chan;
 	struct dma_slave_config dma_rx_sconfig;
 	dma_addr_t dma_bus;
 	unsigned char *dma_buf;
 	int ret;
 
-	rx_chan  = dma_request_slave_channel(sport->port.dev, "rx");
-
-	if (!rx_chan) {
-		dev_err(sport->port.dev, "Dma rx channel request failed!\n");
-		return -ENODEV;
-	}
-
 	dma_buf = devm_kzalloc(sport->port.dev,
 				FSL_UART_RX_DMA_BUFFER_SIZE, GFP_KERNEL);
 
 	if (!dma_buf) {
 		dev_err(sport->port.dev, "Dma rx alloc failed\n");
-		dma_release_channel(rx_chan);
 		return -ENOMEM;
 	}
 
-	dma_bus = dma_map_single(rx_chan->device->dev, dma_buf,
+	dma_bus = dma_map_single(sport->dma_rx_chan->device->dev, dma_buf,
 				FSL_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
 
-	if (dma_mapping_error(rx_chan->device->dev, dma_bus)) {
+	if (dma_mapping_error(sport->dma_rx_chan->device->dev, dma_bus)) {
 		dev_err(sport->port.dev, "dma_map_single rx failed\n");
-		dma_release_channel(rx_chan);
 		return -ENOMEM;
 	}
 
@@ -1034,16 +1016,14 @@ static int lpuart_dma_rx_request(struct uart_port *port)
 	dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	dma_rx_sconfig.src_maxburst = 1;
 	dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
-	ret = dmaengine_slave_config(rx_chan, &dma_rx_sconfig);
+	ret = dmaengine_slave_config(sport->dma_rx_chan, &dma_rx_sconfig);
 
 	if (ret < 0) {
 		dev_err(sport->port.dev,
 				"Dma slave config failed, err = %d\n", ret);
-		dma_release_channel(rx_chan);
 		return ret;
 	}
 
-	sport->dma_rx_chan = rx_chan;
 	sport->dma_rx_buf_virt = dma_buf;
 	sport->dma_rx_buf_bus = dma_bus;
 	sport->dma_rx_in_progress = 0;
@@ -1055,31 +1035,24 @@ static void lpuart_dma_tx_free(struct uart_port *port)
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *dma_chan;
 
 	dma_unmap_single(sport->port.dev, sport->dma_tx_buf_bus,
 			UART_XMIT_SIZE, DMA_TO_DEVICE);
-	dma_chan = sport->dma_tx_chan;
-	sport->dma_tx_chan = NULL;
+
 	sport->dma_tx_buf_bus = 0;
 	sport->dma_tx_buf_virt = NULL;
-	dma_release_channel(dma_chan);
 }
 
 static void lpuart_dma_rx_free(struct uart_port *port)
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *dma_chan;
 
 	dma_unmap_single(sport->port.dev, sport->dma_rx_buf_bus,
 			FSL_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
 
-	dma_chan = sport->dma_rx_chan;
-	sport->dma_rx_chan = NULL;
 	sport->dma_rx_buf_bus = 0;
 	sport->dma_rx_buf_virt = NULL;
-	dma_release_channel(dma_chan);
 }
 
 static int lpuart_startup(struct uart_port *port)
@@ -1098,16 +1071,23 @@ static int lpuart_startup(struct uart_port *port)
 	sport->rxfifo_size = 0x1 << (((temp >> UARTPFIFO_RXSIZE_OFF) &
 		UARTPFIFO_FIFOSIZE_MASK) + 1);
 
-	/* Whether use dma support by dma request results */
-	if (lpuart_dma_tx_request(port) || lpuart_dma_rx_request(port)) {
-		sport->lpuart_dma_use = false;
-	} else {
-		sport->lpuart_dma_use = true;
+	if (sport->dma_rx_chan && !lpuart_dma_rx_request(port))
+	{
+		sport->lpuart_dma_rx_use = true;
 		setup_timer(&sport->lpuart_timer, lpuart_timer_func,
 			    (unsigned long)sport);
+	}
+	else
+		sport->lpuart_dma_rx_use = false;
+
+
+	if (sport->dma_tx_chan && !lpuart_dma_tx_request(port)) {
+		sport->lpuart_dma_tx_use = true;
 		temp = readb(port->membase + UARTCR5);
 		writeb(temp | UARTCR5_TDMAS, port->membase + UARTCR5);
 	}
+	else
+		sport->lpuart_dma_tx_use = false;
 
 	ret = devm_request_irq(port->dev, port->irq, lpuart_int, 0,
 				DRIVER_NAME, sport);
@@ -1178,11 +1158,13 @@ static void lpuart_shutdown(struct uart_port *port)
 
 	devm_free_irq(port->dev, port->irq, sport);
 
-	if (sport->lpuart_dma_use) {
+	if (sport->lpuart_dma_rx_use) {
+		lpuart_dma_rx_free(&sport->port);
 		del_timer_sync(&sport->lpuart_timer);
+	}
 
-		lpuart_dma_tx_free(port);
-		lpuart_dma_rx_free(port);
+	if (sport->lpuart_dma_tx_use) {
+		lpuart_dma_tx_free(&sport->port);
 	}
 }
 
@@ -1305,7 +1287,7 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
 	/* update the per-port timeout */
 	uart_update_timeout(port, termios->c_cflag, baud);
 
-	if (sport->lpuart_dma_use) {
+	if (sport->lpuart_dma_rx_use) {
 		/* Calculate delay for 1.5 DMA buffers */
 		sport->dma_rx_timeout = (sport->port.timeout - HZ / 50) *
 					FSL_UART_RX_DMA_BUFFER_SIZE * 3 /
@@ -1836,6 +1818,16 @@ static int lpuart_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
+	if (!sport->dma_tx_chan)
+		dev_info(sport->port.dev, "DMA tx channel request failed, "
+				"operating without tx DMA\n");
+
+	sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx");
+	if (!sport->dma_rx_chan)
+		dev_info(sport->port.dev, "DMA rx channel request failed, "
+				"operating without rx DMA\n");
+
 	return 0;
 }
 
@@ -1847,6 +1839,12 @@ static int lpuart_remove(struct platform_device *pdev)
 
 	clk_disable_unprepare(sport->clk);
 
+	if (sport->dma_tx_chan)
+		dma_release_channel(sport->dma_tx_chan);
+
+	if (sport->dma_rx_chan)
+		dma_release_channel(sport->dma_rx_chan);
+
 	return 0;
 }