USB: tty: Prune uses of tty_request_room in the USB layer

We have lots of callers that do not need to do this in the first place.
Remove the calls as they both cost CPU and for big buffers can mess up the
multi-page allocation avoidance.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/ark3116.c

@@ -733,7 +733,6 @@ static void ark3116_read_bulk_callback(struct urb *urb)
 
 		tty = tty_port_tty_get(&port->port);
 		if (tty) {
-			tty_buffer_request_room(tty, urb->actual_length + 1);
 			/* overrun is special, not associated with a char */
 			if (unlikely(lsr & UART_LSR_OE))
 				tty_insert_flip_char(tty, 0, TTY_OVERRUN);

drivers/usb/serial/cyberjack.c

@@ -395,7 +395,6 @@ static void cyberjack_read_bulk_callback(struct urb *urb)
 		return;
 	}
 	if (urb->actual_length) {
-		tty_buffer_request_room(tty, urb->actual_length);
 		tty_insert_flip_string(tty, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 	}

drivers/usb/serial/cypress_m8.c

@@ -1307,13 +1307,9 @@ static void cypress_read_int_callback(struct urb *urb)
 		spin_unlock_irqrestore(&priv->lock, flags);
 
 	/* process read if there is data other than line status */
-	if (tty && (bytes > i)) {
-		bytes = tty_buffer_request_room(tty, bytes);
-		for (; i < bytes ; ++i) {
-			dbg("pushing byte number %d - %d - %c", i, data[i],
-					data[i]);
-			tty_insert_flip_char(tty, data[i], tty_flag);
-		}
+	if (tty && bytes > i) {
+		tty_insert_flip_string_fixed_flag(tty, data + i,
+				bytes - i, tty_flag);
 		tty_flip_buffer_push(tty);
 	}
 

drivers/usb/serial/digi_acceleport.c

@@ -1658,7 +1658,6 @@ static int digi_read_inb_callback(struct urb *urb)
 	int port_status = ((unsigned char *)urb->transfer_buffer)[2];
 	unsigned char *data = ((unsigned char *)urb->transfer_buffer) + 3;
 	int flag, throttled;
-	int i;
 	int status = urb->status;
 
 	/* do not process callbacks on closed ports */
@@ -1705,17 +1704,9 @@ static int digi_read_inb_callback(struct urb *urb)
 
 		/* data length is len-1 (one byte of len is port_status) */
 		--len;
-
-		len = tty_buffer_request_room(tty, len);
 		if (len > 0) {
-			/* Hot path */
-			if (flag == TTY_NORMAL)
-				tty_insert_flip_string(tty, data, len);
-			else {
-				for (i = 0; i < len; i++)
-					tty_insert_flip_char(tty,
-								data[i], flag);
-			}
+			tty_insert_flip_string_fixed_flag(tty, data, len,
+									flag);
 			tty_flip_buffer_push(tty);
 		}
 	}

drivers/usb/serial/empeg.c

@@ -346,7 +346,6 @@ static void empeg_read_bulk_callback(struct urb *urb)
 	tty = tty_port_tty_get(&port->port);
 
 	if (urb->actual_length) {
-		tty_buffer_request_room(tty, urb->actual_length);
 		tty_insert_flip_string(tty, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 		bytes_in += urb->actual_length;

drivers/usb/serial/garmin_gps.c

@@ -271,7 +271,6 @@ static void send_to_tty(struct usb_serial_port *port,
 		usb_serial_debug_data(debug, &port->dev,
 					__func__, actual_length, data);
 
-		tty_buffer_request_room(tty, actual_length);
 		tty_insert_flip_string(tty, data, actual_length);
 		tty_flip_buffer_push(tty);
 	}

drivers/usb/serial/io_edgeport.c

@@ -2055,18 +2055,13 @@ static void edge_tty_recv(struct device *dev, struct tty_struct *tty,
 {
 	int cnt;
 
-	do {
-		cnt = tty_buffer_request_room(tty, length);
-		if (cnt < length) {
-			dev_err(dev, "%s - dropping data, %d bytes lost\n",
-					__func__, length - cnt);
-			if (cnt == 0)
-				break;
-		}
-		tty_insert_flip_string(tty, data, cnt);
-		data += cnt;
-		length -= cnt;
-	} while (length > 0);
+	cnt = tty_insert_flip_string(tty, data, length);
+	if (cnt < length) {
+		dev_err(dev, "%s - dropping data, %d bytes lost\n",
+				__func__, length - cnt);
+	}
+	data += cnt;
+	length -= cnt;
 
 	tty_flip_buffer_push(tty);
 }

drivers/usb/serial/io_ti.c

@@ -1820,7 +1820,6 @@ static void edge_tty_recv(struct device *dev, struct tty_struct *tty,
 {
 	int queued;
 
-	tty_buffer_request_room(tty, length);
 	queued = tty_insert_flip_string(tty, data, length);
 	if (queued < length)
 		dev_err(dev, "%s - dropping data, %d bytes lost\n",

drivers/usb/serial/ipaq.c

@@ -747,7 +747,6 @@ static void ipaq_read_bulk_callback(struct urb *urb)
 
 	tty = tty_port_tty_get(&port->port);
 	if (tty && urb->actual_length) {
-		tty_buffer_request_room(tty, urb->actual_length);
 		tty_insert_flip_string(tty, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 		bytes_in += urb->actual_length;

drivers/usb/serial/ipw.c

@@ -172,7 +172,6 @@ static void ipw_read_bulk_callback(struct urb *urb)
 
 	tty = tty_port_tty_get(&port->port);
 	if (tty && urb->actual_length) {
-		tty_buffer_request_room(tty, urb->actual_length);
 		tty_insert_flip_string(tty, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 	}

drivers/usb/serial/ir-usb.c

@@ -462,10 +462,8 @@ static void ir_read_bulk_callback(struct urb *urb)
 		usb_serial_debug_data(debug, &port->dev, __func__,
 						urb->actual_length, data);
 		tty = tty_port_tty_get(&port->port);
-		if (tty_buffer_request_room(tty, urb->actual_length - 1)) {
-			tty_insert_flip_string(tty, data+1, urb->actual_length - 1);
-			tty_flip_buffer_push(tty);
-		}
+		tty_insert_flip_string(tty, data+1, urb->actual_length - 1);
+		tty_flip_buffer_push(tty);
 		tty_kref_put(tty);
 
 		/*

drivers/usb/serial/kl5kusb105.c

@@ -699,7 +699,6 @@ static void klsi_105_read_bulk_callback(struct urb *urb)
 			bytes_sent = urb->actual_length - 2;
 		}
 
-		tty_buffer_request_room(tty, bytes_sent);
 		tty_insert_flip_string(tty, data + 2, bytes_sent);
 		tty_flip_buffer_push(tty);
 		tty_kref_put(tty);

drivers/usb/serial/kobil_sct.c

@@ -388,7 +388,6 @@ static void kobil_read_int_callback(struct urb *urb)
 		*/
 		/* END DEBUG */
 
-		tty_buffer_request_room(tty, urb->actual_length);
 		tty_insert_flip_string(tty, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 	}

drivers/usb/serial/mos7720.c

@@ -290,7 +290,6 @@ static void mos7720_bulk_in_callback(struct urb *urb)
 
 	tty = tty_port_tty_get(&port->port);
 	if (tty && urb->actual_length) {
-		tty_buffer_request_room(tty, urb->actual_length);
 		tty_insert_flip_string(tty, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 	}

drivers/usb/serial/mos7840.c

@@ -764,7 +764,6 @@ static void mos7840_bulk_in_callback(struct urb *urb)
 	if (urb->actual_length) {
 		tty = tty_port_tty_get(&mos7840_port->port->port);
 		if (tty) {
-			tty_buffer_request_room(tty, urb->actual_length);
 			tty_insert_flip_string(tty, data, urb->actual_length);
 			dbg(" %s ", data);
 			tty_flip_buffer_push(tty);

drivers/usb/serial/navman.c

@@ -66,7 +66,6 @@ static void navman_read_int_callback(struct urb *urb)
 
 	tty = tty_port_tty_get(&port->port);
 	if (tty && urb->actual_length) {
-		tty_buffer_request_room(tty, urb->actual_length);
 		tty_insert_flip_string(tty, data, urb->actual_length);
 		tty_flip_buffer_push(tty);
 	}

drivers/usb/serial/opticon.c

@@ -55,7 +55,6 @@ static void opticon_bulk_callback(struct urb *urb)
 	int status = urb->status;
 	struct tty_struct *tty;
 	int result;
-	int available_room = 0;
 	int data_length;
 
 	dbg("%s - port %d", __func__, port->number);
@@ -96,13 +95,9 @@ static void opticon_bulk_callback(struct urb *urb)
 			/* real data, send it to the tty layer */
 			tty = tty_port_tty_get(&port->port);
 			if (tty) {
-				available_room = tty_buffer_request_room(tty,
-								data_length);
-				if (available_room) {
-					tty_insert_flip_string(tty, data,
-							       available_room);
-					tty_flip_buffer_push(tty);
-				}
+				tty_insert_flip_string(tty, data,
+							       data_length);
+				tty_flip_buffer_push(tty);
 				tty_kref_put(tty);
 			}
 		} else {

drivers/usb/serial/option.c

@@ -964,7 +964,6 @@ static void option_indat_callback(struct urb *urb)
 	} else {
 		tty = tty_port_tty_get(&port->port);
 		if (urb->actual_length) {
-			tty_buffer_request_room(tty, urb->actual_length);
 			tty_insert_flip_string(tty, data, urb->actual_length);
 			tty_flip_buffer_push(tty);
 		} else 

drivers/usb/serial/pl2303.c

@@ -1042,7 +1042,6 @@ static void pl2303_push_data(struct tty_struct *tty,
 		tty_flag = TTY_FRAME;
 	dbg("%s - tty_flag = %d", __func__, tty_flag);
 
-	tty_buffer_request_room(tty, urb->actual_length + 1);
 	/* overrun is special, not associated with a char */
 	if (line_status & UART_OVERRUN_ERROR)
 		tty_insert_flip_char(tty, 0, TTY_OVERRUN);

drivers/usb/serial/sierra.c

@@ -595,8 +595,6 @@ static void sierra_indat_callback(struct urb *urb)
 		if (urb->actual_length) {
 			tty = tty_port_tty_get(&port->port);
 			if (tty) {
-				tty_buffer_request_room(tty,
-					urb->actual_length);
 				tty_insert_flip_string(tty, data,
 					urb->actual_length);
 				tty_flip_buffer_push(tty);

drivers/usb/serial/spcp8x5.c

@@ -677,7 +677,6 @@ static void spcp8x5_read_bulk_callback(struct urb *urb)
 	struct tty_struct *tty;
 	unsigned char *data = urb->transfer_buffer;
 	unsigned long flags;
-	int i;
 	int result = urb->status;
 	u8 status;
 	char tty_flag;
@@ -726,12 +725,11 @@ static void spcp8x5_read_bulk_callback(struct urb *urb)
 
 	tty = tty_port_tty_get(&port->port);
 	if (tty && urb->actual_length) {
-		tty_buffer_request_room(tty, urb->actual_length + 1);
 		/* overrun is special, not associated with a char */
 		if (status & UART_OVERRUN_ERROR)
 			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		for (i = 0; i < urb->actual_length; ++i)
-			tty_insert_flip_char(tty, data[i], tty_flag);
+		tty_insert_flip_string_fixed_flag(tty, data,
+						urb->actual_length, tty_flag);
 		tty_flip_buffer_push(tty);
 	}
 	tty_kref_put(tty);

drivers/usb/serial/symbolserial.c

@@ -51,7 +51,6 @@ static void symbol_int_callback(struct urb *urb)
 	int status = urb->status;
 	struct tty_struct *tty;
 	int result;
-	int available_room = 0;
 	int data_length;
 
 	dbg("%s - port %d", __func__, port->number);
@@ -89,13 +88,8 @@ static void symbol_int_callback(struct urb *urb)
 		 */
 		tty = tty_port_tty_get(&port->port);
 		if (tty) {
-			available_room = tty_buffer_request_room(tty,
-							data_length);
-			if (available_room) {
-				tty_insert_flip_string(tty, &data[1],
-						       available_room);
-				tty_flip_buffer_push(tty);
-			}
+			tty_insert_flip_string(tty, &data[1], data_length);
+			tty_flip_buffer_push(tty);
 			tty_kref_put(tty);
 		}
 	} else {

drivers/usb/serial/ti_usb_3410_5052.c

@@ -1271,14 +1271,13 @@ static void ti_recv(struct device *dev, struct tty_struct *tty,
 	int cnt;
 
 	do {
-		cnt = tty_buffer_request_room(tty, length);
+		cnt = tty_insert_flip_string(tty, data, length);
 		if (cnt < length) {
 			dev_err(dev, "%s - dropping data, %d bytes lost\n",
 						__func__, length - cnt);
 			if (cnt == 0)
 				break;
 		}
-		tty_insert_flip_string(tty, data, cnt);
 		tty_flip_buffer_push(tty);
 		data += cnt;
 		length -= cnt;

drivers/usb/serial/visor.c

@@ -503,13 +503,9 @@ static void visor_read_bulk_callback(struct urb *urb)
 	if (urb->actual_length) {
 		tty = tty_port_tty_get(&port->port);
 		if (tty) {
-			available_room = tty_buffer_request_room(tty,
-							urb->actual_length);
-			if (available_room) {
-				tty_insert_flip_string(tty, data,
-							available_room);
-				tty_flip_buffer_push(tty);
-			}
+			tty_insert_flip_string(tty, data,
+						urb->actual_length);
+			tty_flip_buffer_push(tty);
 			tty_kref_put(tty);
 		}
 		spin_lock(&priv->lock);