[v2,5/5] serial: imx: use Tx ready rather than Tx empty irq

Commit Message

Sergey Organov Aug. 28, 2019, 6:37 p.m. UTC

This should help to avoid unnecessary gaps in transmission while
adding little overhead due to low default Tx threshold level (2
bytes).

Signed-off-by: Sergey Organov <[e-mail]>
---
 drivers/tty/serial/imx.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

Patch

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index e89045a..87c58f9 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -439,7 +439,7 @@  static void imx_uart_stop_tx(struct uart_port *port)
 		return;
 
 	ucr1 = imx_uart_readl(sport, UCR1);
-	imx_uart_writel(sport, ucr1 & ~UCR1_TXMPTYEN, UCR1);
+	imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
 
 	/* in rs485 mode disable transmitter if shifter is empty */
 	if (port->rs485.flags & SER_RS485_ENABLED &&
@@ -517,7 +517,7 @@  static inline void imx_uart_transmit_buffer(struct imx_port *sport)
 		 * and the TX IRQ is disabled.
 		 **/
 		ucr1 = imx_uart_readl(sport, UCR1);
-		ucr1 &= ~UCR1_TXMPTYEN;
+		ucr1 &= ~UCR1_TRDYEN;
 		if (sport->dma_is_txing) {
 			ucr1 |= UCR1_TXDMAEN;
 			imx_uart_writel(sport, ucr1, UCR1);
@@ -679,7 +679,7 @@  static void imx_uart_start_tx(struct uart_port *port)
 
 	if (!sport->dma_is_enabled) {
 		ucr1 = imx_uart_readl(sport, UCR1);
-		imx_uart_writel(sport, ucr1 | UCR1_TXMPTYEN, UCR1);
+		imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
 	}
 
 	if (sport->dma_is_enabled) {
@@ -688,7 +688,7 @@  static void imx_uart_start_tx(struct uart_port *port)
 			 * disable TX DMA to let TX interrupt to send X-char */
 			ucr1 = imx_uart_readl(sport, UCR1);
 			ucr1 &= ~UCR1_TXDMAEN;
-			ucr1 |= UCR1_TXMPTYEN;
+			ucr1 |= UCR1_TRDYEN;
 			imx_uart_writel(sport, ucr1, UCR1);
 			return;
 		}
@@ -874,7 +874,7 @@  static irqreturn_t imx_uart_int(int irq, void *dev_id)
 		usr1 &= ~USR1_RRDY;
 	if ((ucr2 & UCR2_ATEN) == 0)
 		usr1 &= ~USR1_AGTIM;
-	if ((ucr1 & UCR1_TXMPTYEN) == 0)
+	if ((ucr1 & UCR1_TRDYEN) == 0)
 		usr1 &= ~USR1_TRDY;
 	if ((ucr4 & UCR4_TCEN) == 0)
 		usr2 &= ~USR2_TXDC;
@@ -1474,7 +1474,7 @@  static void imx_uart_shutdown(struct uart_port *port)
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 	ucr1 = imx_uart_readl(sport, UCR1);
-	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
+	ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
 
 	imx_uart_writel(sport, ucr1, UCR1);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
@@ -1778,7 +1778,7 @@  static int imx_uart_poll_init(struct uart_port *port)
 		ucr1 |= IMX1_UCR1_UARTCLKEN;
 
 	ucr1 |= UCR1_UARTEN;
-	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN);
+	ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
 
 	ucr2 |= UCR2_RXEN;
 	ucr2 &= ~UCR2_ATEN;
@@ -1938,7 +1938,7 @@  imx_uart_console_write(struct console *co, const char *s, unsigned int count)
 	if (imx_uart_is_imx1(sport))
 		ucr1 |= IMX1_UCR1_UARTCLKEN;
 	ucr1 |= UCR1_UARTEN;
-	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
+	ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
 
 	imx_uart_writel(sport, ucr1, UCR1);
 
@@ -2294,7 +2294,7 @@  static int imx_uart_probe(struct platform_device *pdev)
 	/* Disable interrupts before requesting them */
 	ucr1 = imx_uart_readl(sport, UCR1);
 	ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
-		 UCR1_TXMPTYEN | UCR1_RTSDEN);
+		 UCR1_TRDYEN | UCR1_RTSDEN);
 	imx_uart_writel(sport, ucr1, UCR1);
 
 	if (!imx_uart_is_imx1(sport) && sport->dte_mode) {