Merge branch 'linux-2.6'

1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index d57bf3e708d8..430997e33fc4 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -96,6 +96,7 @@
 
  /* PDC registers */
 #define UART_PUT_PTCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
+#define UART_GET_TCR(port)      __raw_readl((port)->membase + ATMEL_PDC_TCR)
 #define UART_GET_PTSR(port)	__raw_readl((port)->membase + ATMEL_PDC_PTSR)
 
 #define UART_PUT_RPR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
@@ -106,6 +107,7 @@
 
 #define UART_PUT_TPR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
 #define UART_PUT_TCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
+#define UART_GET_TCR(port)	__raw_readl((port)->membase + ATMEL_PDC_TCR)
 
 static int (*atmel_open_hook)(struct uart_port *);
 static void (*atmel_close_hook)(struct uart_port *);
@@ -562,17 +564,22 @@ static void atmel_tx_dma(struct uart_port *port)
 	struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
 	int count;
 
+	/* nothing left to transmit? */
+	if (UART_GET_TCR(port))
+		return;
+
 	xmit->tail += pdc->ofs;
 	xmit->tail &= UART_XMIT_SIZE - 1;
 
 	port->icount.tx += pdc->ofs;
 	pdc->ofs = 0;
 
-	if (!uart_circ_empty(xmit)) {
-		/* more to transmit - setup next transfer */
+	/* more to transmit - setup next transfer */
 
-		/* disable PDC transmit */
-		UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
+	/* disable PDC transmit */
+	UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
+
+	if (!uart_circ_empty(xmit)) {
 		dma_sync_single_for_device(port->dev,
 					   pdc->dma_addr,
 					   pdc->dma_size,
@@ -586,11 +593,6 @@ static void atmel_tx_dma(struct uart_port *port)
 		/* re-enable PDC transmit and interrupts */
 		UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
 		UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
-	} else {
-		/* nothing left to transmit - disable the transmitter */
-
-		/* disable PDC transmit */
-		UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
 	}
 
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
@@ -1274,6 +1276,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count)
 {
 	struct uart_port *port = &atmel_ports[co->index].uart;
 	unsigned int status, imr;
+	unsigned int pdc_tx;
 
 	/*
 	 * First, save IMR and then disable interrupts
@@ -1281,6 +1284,10 @@ static void atmel_console_write(struct console *co, const char *s, u_int count)
 	imr = UART_GET_IMR(port);
 	UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);
 
+	/* Store PDC transmit status and disable it */
+	pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN;
+	UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
+
 	uart_console_write(port, s, count, atmel_console_putchar);
 
 	/*
@@ -1290,6 +1297,11 @@ static void atmel_console_write(struct console *co, const char *s, u_int count)
 	do {
 		status = UART_GET_CSR(port);
 	} while (!(status & ATMEL_US_TXRDY));
+
+	/* Restore PDC transmit status */
+	if (pdc_tx)
+		UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
+
 	/* set interrupts back the way they were */
 	UART_PUT_IER(port, imr);
 }