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>

24 files changed, 25 insertions, 79 deletions

diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
index 1f75fac..547c944 100644
--- a/drivers/usb/serial/ark3116.c
+++ b/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);
diff --git a/drivers/usb/serial/cyberjack.c b/drivers/usb/serial/cyberjack.c
index 036f999..f744ab7 100644
--- a/drivers/usb/serial/cyberjack.c
+++ b/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);
 	}
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index c349f79..3a5d57f 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/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);
 	}
 
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index 3b63484..3817228 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/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);
 		}
 	}
diff --git a/drivers/usb/serial/empeg.c b/drivers/usb/serial/empeg.c
index d02e604..5f740a1 100644
--- a/drivers/usb/serial/empeg.c
+++ b/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;
diff --git a/drivers/usb/serial/garmin_gps.c b/drivers/usb/serial/garmin_gps.c
index 6bbedfb..a42b29a 100644
--- a/drivers/usb/serial/garmin_gps.c
+++ b/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);
 	}
diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index 66fb58f..3ef8df0 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/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);
 }
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 98e5045..aa876f7 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/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",
diff --git a/drivers/usb/serial/ipaq.c b/drivers/usb/serial/ipaq.c
index d6231c3..3fea929 100644
--- a/drivers/usb/serial/ipaq.c
+++ b/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;
diff --git a/drivers/usb/serial/ipw.c b/drivers/usb/serial/ipw.c
index c0afa7a..e1d0784 100644
--- a/drivers/usb/serial/ipw.c
+++ b/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);
 	}
diff --git a/drivers/usb/serial/ir-usb.c b/drivers/usb/serial/ir-usb.c
index fc2ab81..c3e5d50 100644
--- a/drivers/usb/serial/ir-usb.c
+++ b/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);
 
 		/*
diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index 2dbe22a..8eef91b 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/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);
diff --git a/drivers/usb/serial/kobil_sct.c b/drivers/usb/serial/kobil_sct.c
index fc78553..c113a2a 100644
--- a/drivers/usb/serial/kobil_sct.c
+++ b/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);
 	}
diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 546b29f..0d47f2c 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/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);
 	}
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index c89a89c..2fda1c0 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/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);
diff --git a/drivers/usb/serial/navman.c b/drivers/usb/serial/navman.c
index efa61bc..04a6cbb 100644
--- a/drivers/usb/serial/navman.c
+++ b/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);
 	}
diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index 7732866..f37476e 100644
--- a/drivers/usb/serial/opticon.c
+++ b/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 {
diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index f6646b3..68c7457 100644
--- a/drivers/usb/serial/option.c
+++ b/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 
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 767000c..a3e5a56 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/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);
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index fcec466..c012e51 100644
--- a/drivers/usb/serial/sierra.c
+++ b/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);
diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c
index 067e95a..cf508e2 100644
--- a/drivers/usb/serial/spcp8x5.c
+++ b/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);
diff --git a/drivers/usb/serial/symbolserial.c b/drivers/usb/serial/symbolserial.c
index 1a76bc5..7239888 100644
--- a/drivers/usb/serial/symbolserial.c
+++ b/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 {
diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index 1e9dc88..0afe5c7 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/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;
diff --git a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c
index 4f7945e..0949427 100644
--- a/drivers/usb/serial/visor.c
+++ b/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);