[PATCH 2/2] pl011: factor our FIFO to TTY code

@@ -144,6 +144,62 @@ struct uart_amba_port {
 };
 
 /*
+ * Reads up to 256 characters from the FIFO or until it's empty and
+ * inserts them into the TTY layer. Returns the number of characters
+ * read from the FIFO.
+ */
+static int pl011_fifo_to_tty(struct uart_amba_port *uap)
+{
+	u16 status, ch;
+	unsigned int flag, max_count = 256;
+	int fifotaken = 0;
+
+	while (max_count--) {
+		status = readw(uap->port.membase + UART01x_FR);
+		if (status & UART01x_FR_RXFE)
+			break;
+
+		/* Take chars from the FIFO and update status */
+		ch = readw(uap->port.membase + UART01x_DR) |
+			UART_DUMMY_DR_RX;
+		flag = TTY_NORMAL;
+		uap->port.icount.rx++;
+		fifotaken++;
+
+		if (unlikely(ch & UART_DR_ERROR)) {
+			if (ch & UART011_DR_BE) {
+				ch &= ~(UART011_DR_FE | UART011_DR_PE);
+				uap->port.icount.brk++;
+				if (uart_handle_break(&uap->port))
+					continue;
+			} else if (ch & UART011_DR_PE)
+				uap->port.icount.parity++;
+			else if (ch & UART011_DR_FE)
+				uap->port.icount.frame++;
+			if (ch & UART011_DR_OE)
+				uap->port.icount.overrun++;
+
+			ch &= uap->port.read_status_mask;
+
+			if (ch & UART011_DR_BE)
+				flag = TTY_BREAK;
+			else if (ch & UART011_DR_PE)
+				flag = TTY_PARITY;
+			else if (ch & UART011_DR_FE)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(&uap->port, ch & 255))
+			continue;
+
+		uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
+	}
+
+	return fifotaken;
+}
+
+
+/*
  * All the DMA operation mode stuff goes inside this ifdef.
  * This assumes that you have a generic DMA device interface,
  * no custom DMA interfaces are supported.

@@ -634,7 +690,6 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap,
 	struct pl011_sgbuf *sgbuf = use_buf_b ?
 		&uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
 	struct device *dev = uap->dmarx.chan->device->dev;
-	unsigned int status, ch, flag;
 	int dma_count = 0;
 	u32 fifotaken = 0; /* only used for vdbg() */
 

@@ -671,56 +726,16 @@ static void pl011_dma_rx_chars(struct uart_amba_port *uap,
 
 		/*
 		 * If we read all the DMA'd characters, and we had an
-		 * incomplete buffer, that could be due to an rx error,
-		 * or maybe we just timed out. Read any pending chars
-		 * and check the error status.
+		 * incomplete buffer, that could be due to an rx error, or
+		 * maybe we just timed out. Read any pending chars and check
+		 * the error status.
+		 *
+		 * Error conditions will only occur in the FIFO, these will
+		 * trigger an immediate interrupt and stop the DMA job, so we
+		 * will always find the error in the FIFO, never in the DMA
+		 * buffer.
 		 */
-		while (1) {
-			status = readw(uap->port.membase + UART01x_FR);
-			if (status & UART01x_FR_RXFE)
-				break;
-
-			/* Take chars from the FIFO and update status */
-			ch = readw(uap->port.membase + UART01x_DR) |
-			       UART_DUMMY_DR_RX;
-			flag = TTY_NORMAL;
-			uap->port.icount.rx++;
-			fifotaken++;
-
-			/*
-			 * Error conditions will only occur in the FIFO,
-			 * these will trigger an immediate interrupt and
-			 * stop the DMA job, so we will always find the
-			 * error in the FIFO, never in the DMA buffer.
-			 */
-			if (unlikely(ch & UART_DR_ERROR)) {
-				if (ch & UART011_DR_BE) {
-					ch &= ~(UART011_DR_FE | UART011_DR_PE);
-					uap->port.icount.brk++;
-					if (uart_handle_break(&uap->port))
-						continue;
-				} else if (ch & UART011_DR_PE)
-					uap->port.icount.parity++;
-				else if (ch & UART011_DR_FE)
-					uap->port.icount.frame++;
-				if (ch & UART011_DR_OE)
-					uap->port.icount.overrun++;
-
-				ch &= uap->port.read_status_mask;
-
-				if (ch & UART011_DR_BE)
-					flag = TTY_BREAK;
-				else if (ch & UART011_DR_PE)
-					flag = TTY_PARITY;
-				else if (ch & UART011_DR_FE)
-					flag = TTY_FRAME;
-			}
-
-			if (uart_handle_sysrq_char(&uap->port, ch & 255))
-				continue;
-
-			uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
-		}
+		fifotaken = pl011_fifo_to_tty(uap);
 	}
 
 	spin_unlock(&uap->port.lock);

@@ -1036,49 +1051,9 @@ static void pl011_enable_ms(struct uart_port *port)
 static void pl011_rx_chars(struct uart_amba_port *uap)
 {
 	struct tty_struct *tty = uap->port.state->port.tty;
-	unsigned int status, ch, flag, max_count = 256;
 
-	status = readw(uap->port.membase + UART01x_FR);
-	while ((status & UART01x_FR_RXFE) == 0 && max_count--) {
-		ch = readw(uap->port.membase + UART01x_DR) | UART_DUMMY_DR_RX;
-		flag = TTY_NORMAL;
-		uap->port.icount.rx++;
+	pl011_fifo_to_tty(uap);
 
-		/*
-		 * Note that the error handling code is
-		 * out of the main execution path
-		 */
-		if (unlikely(ch & UART_DR_ERROR)) {
-			if (ch & UART011_DR_BE) {
-				ch &= ~(UART011_DR_FE | UART011_DR_PE);
-				uap->port.icount.brk++;
-				if (uart_handle_break(&uap->port))
-					goto ignore_char;
-			} else if (ch & UART011_DR_PE)
-				uap->port.icount.parity++;
-			else if (ch & UART011_DR_FE)
-				uap->port.icount.frame++;
-			if (ch & UART011_DR_OE)
-				uap->port.icount.overrun++;
-
-			ch &= uap->port.read_status_mask;
-
-			if (ch & UART011_DR_BE)
-				flag = TTY_BREAK;
-			else if (ch & UART011_DR_PE)
-				flag = TTY_PARITY;
-			else if (ch & UART011_DR_FE)
-				flag = TTY_FRAME;
-		}
-
-		if (uart_handle_sysrq_char(&uap->port, ch & 255))
-			goto ignore_char;
-
-		uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
-
-	ignore_char:
-		status = readw(uap->port.membase + UART01x_FR);
-	}
 	spin_unlock(&uap->port.lock);
 	tty_flip_buffer_push(tty);
 	/*