TTY: switch tty_buffer_request_room to tty_port

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty pointer in
many call sites. Only tty_port will be needed and hence no more
tty_port_tty_get calls in those paths.

Here we start with tty_buffer_request_room.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

21 files changed, 60 insertions, 43 deletions

diff --git a/arch/mn10300/kernel/mn10300-serial.c b/arch/mn10300/kernel/mn10300-serial.c
index 81d5cb9b6569..9b2232a78ff9 100644
--- a/arch/mn10300/kernel/mn10300-serial.c
+++ b/arch/mn10300/kernel/mn10300-serial.c
@@ -524,7 +524,8 @@ static int mask_test_and_clear(volatile u8 *ptr, u8 mask)
 static void mn10300_serial_receive_interrupt(struct mn10300_serial_port *port)
 {
         struct uart_icount *icount = &port->uart.icount;
-        struct tty_struct *tty = port->uart.state->port.tty;
+        struct tty_port *port = &port->uart.state->port;
+        struct tty_struct *tty = port->tty;
         unsigned ix;
         int count;
         u8 st, ch, push, status, overrun;
@@ -534,7 +535,7 @@ static void mn10300_serial_receive_interrupt(struct mn10300_serial_port *port)
         push = 0;
 
         count = CIRC_CNT(port->rx_inp, port->rx_outp, MNSC_BUFFER_SIZE);
-        count = tty_buffer_request_room(tty, count);
+        count = tty_buffer_request_room(port, count);
         if (count == 0) {
                 if (!tty->low_latency)
                         tty_flip_buffer_push(tty);
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index e9a0abc6a32f..4ff2503a1bb8 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -554,6 +554,7 @@ int parse_chan_pair(char *str, struct line *line, int device,
 
 void chan_interrupt(struct line *line, struct tty_struct *tty, int irq)
 {
+        struct tty_port *port = &line->port;
         struct chan *chan = line->chan_in;
         int err;
         char c;
@@ -562,7 +563,7 @@ void chan_interrupt(struct line *line, struct tty_struct *tty, int irq)
                 goto out;
 
         do {
-                if (tty && !tty_buffer_request_room(tty, 1)) {
+                if (!tty_buffer_request_room(port, 1)) {
                         schedule_delayed_work(&line->task, 1);
                         goto out;
                 }
diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index b2f35d786025..0b1de715f097 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -888,6 +888,7 @@ static void rx_ready_hdlc(MGSLPC_INFO *info, int eom)
 
 static void rx_ready_async(MGSLPC_INFO *info, int tcd, struct tty_struct *tty)
 {
+        struct tty_port *port = &info->port;
         unsigned char data, status, flag;
         int fifo_count;
         int work = 0;
@@ -913,7 +914,7 @@ static void rx_ready_async(MGSLPC_INFO *info, int tcd, struct tty_struct *tty)
         } else
                 fifo_count = 32;
 
-        tty_buffer_request_room(tty, fifo_count);
+        tty_buffer_request_room(port, fifo_count);
         /* Flush received async data to receive data buffer. */
         while (fifo_count) {
                 data   = read_reg(info, CHA + RXFIFO);
diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index e2a945ee9f05..7093169ee0c9 100644
--- a/drivers/isdn/i4l/isdn_common.c
+++ b/drivers/isdn/i4l/isdn_common.c
@@ -878,6 +878,7 @@ isdn_readbchan(int di, int channel, u_char *buf, u_char *fp, int len, wait_queue
 int
 isdn_readbchan_tty(int di, int channel, struct tty_struct *tty, int cisco_hack)
 {
+        struct tty_port *port = tty->port;
         int count;
         int count_pull;
         int count_put;
@@ -891,7 +892,7 @@ isdn_readbchan_tty(int di, int channel, struct tty_struct *tty, int cisco_hack)
         if (skb_queue_empty(&dev->drv[di]->rpqueue[channel]))
                 return 0;
 
-        len = tty_buffer_request_room(tty, dev->drv[di]->rcvcount[channel]);
+        len = tty_buffer_request_room(port, dev->drv[di]->rcvcount[channel]);
         if (len == 0)
                 return len;
 
diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
index e09dc8a5e743..4f5bcee7cf32 100644
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -60,6 +60,7 @@ static int si2bit[8] =
 static int
 isdn_tty_try_read(modem_info *info, struct sk_buff *skb)
 {
+        struct tty_port *port = &info->port;
         int c;
         int len;
         struct tty_struct *tty;
@@ -68,7 +69,7 @@ isdn_tty_try_read(modem_info *info, struct sk_buff *skb)
         if (!info->online)
                 return 0;
 
-        tty = info->port.tty;
+        tty = port->tty;
         if (!tty)
                 return 0;
 
@@ -81,7 +82,7 @@ isdn_tty_try_read(modem_info *info, struct sk_buff *skb)
 #endif
                 ;
 
-        c = tty_buffer_request_room(tty, len);
+        c = tty_buffer_request_room(port, len);
         if (c < len)
                 return 0;
 
@@ -2230,6 +2231,7 @@ void
 isdn_tty_at_cout(char *msg, modem_info *info)
 {
         struct tty_struct *tty;
+        struct tty_port *port = &info->port;
         atemu *m = &info->emu;
         char *p;
         char c;
@@ -2246,15 +2248,15 @@ isdn_tty_at_cout(char *msg, modem_info *info)
         l = strlen(msg);
 
         spin_lock_irqsave(&info->readlock, flags);
-        tty = info->port.tty;
-        if ((info->port.flags & ASYNC_CLOSING) || (!tty)) {
+        tty = port->tty;
+        if ((port->flags & ASYNC_CLOSING) || (!tty)) {
                 spin_unlock_irqrestore(&info->readlock, flags);
                 return;
         }
 
         /* use queue instead of direct, if online and */
         /* data is in queue or buffer is full */
-        if (info->online && ((tty_buffer_request_room(tty, l) < l) ||
+        if (info->online && ((tty_buffer_request_room(port, l) < l) ||
                              !skb_queue_empty(&dev->drv[info->isdn_driver]->rpqueue[info->isdn_channel]))) {
                 skb = alloc_skb(l, GFP_ATOMIC);
                 if (!skb) {
diff --git a/drivers/staging/dgrp/dgrp_net_ops.c b/drivers/staging/dgrp/dgrp_net_ops.c
index 2d1bbfd5b67c..c0aeaaa094f1 100644
--- a/drivers/staging/dgrp/dgrp_net_ops.c
+++ b/drivers/staging/dgrp/dgrp_net_ops.c
@@ -211,7 +211,7 @@ static void dgrp_input(struct ch_struct *ch)
         data_len = (ch->ch_rin - ch->ch_rout) & RBUF_MASK;
 
         /* len is the amount of data we are going to transfer here */
-        len = tty_buffer_request_room(tty, data_len);
+        len = tty_buffer_request_room(&ch->port, data_len);
 
         /* Check DPA flow control */
         if ((nd->nd_dpa_debug) &&
@@ -2956,7 +2956,7 @@ check_query:
                             I_BRKINT(ch->ch_tun.un_tty) &&
                             !(I_IGNBRK(ch->ch_tun.un_tty))) {
 
-                                tty_buffer_request_room(ch->ch_tun.un_tty, 1);
+                                tty_buffer_request_room(&ch->port, 1);
                                 tty_insert_flip_char(ch->ch_tun.un_tty, 0, TTY_BREAK);
                                 tty_flip_buffer_push(ch->ch_tun.un_tty);
 
diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c
index b09c8d1f9a66..b85acc74eb0d 100644
--- a/drivers/tty/cyclades.c
+++ b/drivers/tty/cyclades.c
@@ -442,6 +442,7 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
 {
         struct cyclades_port *info;
         struct tty_struct *tty;
+        struct tty_port *port;
         int len, index = cinfo->bus_index;
         u8 ivr, save_xir, channel, save_car, data, char_count;
 
@@ -452,11 +453,12 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
         save_xir = readb(base_addr + (CyRIR << index));
         channel = save_xir & CyIRChannel;
         info = &cinfo->ports[channel + chip * 4];
+        port = &info->port;
         save_car = cyy_readb(info, CyCAR);
         cyy_writeb(info, CyCAR, save_xir);
         ivr = cyy_readb(info, CyRIVR) & CyIVRMask;
 
-        tty = tty_port_tty_get(&info->port);
+        tty = tty_port_tty_get(port);
         /* if there is nowhere to put the data, discard it */
         if (tty == NULL) {
                 if (ivr == CyIVRRxEx) { /* exception */
@@ -487,14 +489,14 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
                         tty_kref_put(tty);
                         return;
                 }
-                if (tty_buffer_request_room(tty, 1)) {
+                if (tty_buffer_request_room(port, 1)) {
                         if (data & info->read_status_mask) {
                                 if (data & CyBREAK) {
                                         tty_insert_flip_char(tty,
                                                 cyy_readb(info, CyRDSR),
                                                 TTY_BREAK);
                                         info->icount.rx++;
-                                        if (info->port.flags & ASYNC_SAK)
+                                        if (port->flags & ASYNC_SAK)
                                                 do_SAK(tty);
                                 } else if (data & CyFRAME) {
                                         tty_insert_flip_char(tty,
@@ -552,7 +554,7 @@ static void cyy_chip_rx(struct cyclades_card *cinfo, int chip,
                         info->mon.char_max = char_count;
                 info->mon.char_last = char_count;
 #endif
-                len = tty_buffer_request_room(tty, char_count);
+                len = tty_buffer_request_room(port, char_count);
                 while (len--) {
                         data = cyy_readb(info, CyRDSR);
                         tty_insert_flip_char(tty, data, TTY_NORMAL);
@@ -928,6 +930,7 @@ static void cyz_handle_rx(struct cyclades_port *info, struct tty_struct *tty)
 {
         struct BUF_CTRL __iomem *buf_ctrl = info->u.cyz.buf_ctrl;
         struct cyclades_card *cinfo = info->card;
+        struct tty_port *port = &info->port;
         unsigned int char_count;
         int len;
 #ifdef BLOCKMOVE
@@ -983,7 +986,7 @@ static void cyz_handle_rx(struct cyclades_port *info, struct tty_struct *tty)
                                 info->idle_stats.recv_bytes += len;
                         }
 #else
-                        len = tty_buffer_request_room(tty, char_count);
+                        len = tty_buffer_request_room(port, char_count);
                         while (len--) {
                                 data = readb(cinfo->base_addr + rx_bufaddr +
                                                 new_rx_get);
diff --git a/drivers/tty/ehv_bytechan.c b/drivers/tty/ehv_bytechan.c
index c117d775a22f..af97e39d641c 100644
--- a/drivers/tty/ehv_bytechan.c
+++ b/drivers/tty/ehv_bytechan.c
@@ -386,7 +386,7 @@ static irqreturn_t ehv_bc_tty_rx_isr(int irq, void *data)
          * read from the byte channel will be accepted by the TTY layer.
          */
         ev_byte_channel_poll(bc->handle, &rx_count, &tx_count);
-        count = tty_buffer_request_room(ttys, rx_count);
+        count = tty_buffer_request_room(&bc->port, rx_count);
 
         /* 'count' is the maximum amount of data the TTY layer can accept at
          * this time.  However, during testing, I was never able to get 'count'
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index 13ee53bd0bf6..3d2ea92b8505 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -629,7 +629,7 @@ int hvc_poll(struct hvc_struct *hp)
 
         /* Read data if any */
         for (;;) {
-                int count = tty_buffer_request_room(tty, N_INBUF);
+                int count = tty_buffer_request_room(&hp->port, N_INBUF);
 
                 /* If flip is full, just reschedule a later read */
                 if (count == 0) {
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 877635733952..4a0ab98e9a63 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -609,7 +609,7 @@ static int hvcs_io(struct hvcs_struct *hvcsd)
         /* remove the read masks */
         hvcsd->todo_mask &= ~(HVCS_READ_MASK);
 
-        if (tty_buffer_request_room(tty, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) {
+        if (tty_buffer_request_room(&hvcsd->port, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) {
                 got = hvc_get_chars(unit_address,
                                 &buf[0],
                                 HVCS_BUFF_LEN);
diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
index ad0caf176808..42d5eb0125b3 100644
--- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
@@ -245,7 +245,8 @@ static void cpm_uart_int_rx(struct uart_port *port)
         int i;
         unsigned char ch;
         u8 *cp;
-        struct tty_struct *tty = port->state->port.tty;
+        struct tty_port *tport = &port->state->port;
+        struct tty_struct *tty = tport->tty;
         struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
         cbd_t __iomem *bdp;
         u16 status;
@@ -276,7 +277,7 @@ static void cpm_uart_int_rx(struct uart_port *port)
                 /* If we have not enough room in tty flip buffer, then we try
                  * later, which will be the next rx-interrupt or a timeout
                  */
-                if(tty_buffer_request_room(tty, i) < i) {
+                if (tty_buffer_request_room(tport, i) < i) {
                         printk(KERN_WARNING "No room in flip buffer\n");
                         return;
                 }
diff --git a/drivers/tty/serial/ioc4_serial.c b/drivers/tty/serial/ioc4_serial.c
index c4e30b841f94..710ce87ffbeb 100644
--- a/drivers/tty/serial/ioc4_serial.c
+++ b/drivers/tty/serial/ioc4_serial.c
@@ -2356,7 +2356,7 @@ static void receive_chars(struct uart_port *the_port)
         spin_lock_irqsave(&the_port->lock, pflags);
         tty = state->port.tty;
 
-        request_count = tty_buffer_request_room(tty, IOC4_MAX_CHARS);
+        request_count = tty_buffer_request_room(&state->port, IOC4_MAX_CHARS);
 
         if (request_count > 0) {
                 icount = &the_port->icount;
diff --git a/drivers/tty/serial/jsm/jsm_tty.c b/drivers/tty/serial/jsm/jsm_tty.c
index 4c00c5550b1a..3969e54744cc 100644
--- a/drivers/tty/serial/jsm/jsm_tty.c
+++ b/drivers/tty/serial/jsm/jsm_tty.c
@@ -521,6 +521,7 @@ void jsm_input(struct jsm_channel *ch)
 {
         struct jsm_board *bd;
         struct tty_struct *tp;
+        struct tty_port *port;
         u32 rmask;
         u16 head;
         u16 tail;
@@ -536,7 +537,8 @@ void jsm_input(struct jsm_channel *ch)
         if (!ch)
                 return;
 
-        tp = ch->uart_port.state->port.tty;
+        port = &ch->uart_port.state->port;
+        tp = port->tty;
 
         bd = ch->ch_bd;
         if(!bd)
@@ -600,7 +602,7 @@ void jsm_input(struct jsm_channel *ch)
                 return;
         }
 
-        len = tty_buffer_request_room(tp, data_len);
+        len = tty_buffer_request_room(port, data_len);
         n = len;
 
         /*
diff --git a/drivers/tty/serial/mpsc.c b/drivers/tty/serial/mpsc.c
index 6a9c6605666a..50366863cfa3 100644
--- a/drivers/tty/serial/mpsc.c
+++ b/drivers/tty/serial/mpsc.c
@@ -937,7 +937,8 @@ static int serial_polled;
 static int mpsc_rx_intr(struct mpsc_port_info *pi)
 {
         struct mpsc_rx_desc *rxre;
-        struct tty_struct *tty = pi->port.state->port.tty;
+        struct tty_port *port = &pi->port.state->port;
+        struct tty_struct *tty = port->tty;
         u32     cmdstat, bytes_in, i;
         int     rc = 0;
         u8      *bp;
@@ -968,8 +969,7 @@ static int mpsc_rx_intr(struct mpsc_port_info *pi)
                 }
 #endif
                 /* Following use of tty struct directly is deprecated */
-                if (unlikely(tty_buffer_request_room(tty, bytes_in)
-                                        < bytes_in)) {
+                if (tty_buffer_request_room(port, bytes_in) < bytes_in) {
                         if (tty->low_latency)
                                 tty_flip_buffer_push(tty);
                         /*
diff --git a/drivers/tty/serial/mrst_max3110.c b/drivers/tty/serial/mrst_max3110.c
index 58734d7e746d..776431ff0190 100644
--- a/drivers/tty/serial/mrst_max3110.c
+++ b/drivers/tty/serial/mrst_max3110.c
@@ -339,6 +339,7 @@ static int
 receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
 {
         struct uart_port *port = &max->port;
+        struct tty_port *tport;
         struct tty_struct *tty;
         char buf[M3110_RX_FIFO_DEPTH];
         int r, w, usable;
@@ -347,7 +348,8 @@ receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
         if (!port->state)
                 return 0;
 
-        tty = tty_port_tty_get(&port->state->port);
+        tport = &port->state->port;
+        tty = tty_port_tty_get(tport);
         if (!tty)
                 return 0;
 
@@ -370,7 +372,7 @@ receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
         }
 
         for (r = 0; w; r += usable, w -= usable) {
-                usable = tty_buffer_request_room(tty, w);
+                usable = tty_buffer_request_room(tport, w);
                 if (usable) {
                         tty_insert_flip_string(tty, buf + r, usable);
                         port->icount.rx += usable;
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 8318925fbf6b..4f1774be2a8c 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -629,15 +629,16 @@ static int dma_push_rx(struct eg20t_port *priv, int size)
         struct tty_struct *tty;
         int room;
         struct uart_port *port = &priv->port;
+        struct tty_port *tport = &port->state->port;
 
         port = &priv->port;
-        tty = tty_port_tty_get(&port->state->port);
+        tty = tty_port_tty_get(tport);
         if (!tty) {
                 dev_dbg(priv->port.dev, "%s:tty is busy now", __func__);
                 return 0;
         }
 
-        room = tty_buffer_request_room(tty, size);
+        room = tty_buffer_request_room(tport, size);
 
         if (room < size)
                 dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 61477567423f..cf96314770fb 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -596,7 +596,8 @@ static void sci_transmit_chars(struct uart_port *port)
 static void sci_receive_chars(struct uart_port *port)
 {
         struct sci_port *sci_port = to_sci_port(port);
-        struct tty_struct *tty = port->state->port.tty;
+        struct tty_port *tport = &port->state->port;
+        struct tty_struct *tty = tport->tty;
         int i, count, copied = 0;
         unsigned short status;
         unsigned char flag;
@@ -607,7 +608,7 @@ static void sci_receive_chars(struct uart_port *port)
 
         while (1) {
                 /* Don't copy more bytes than there is room for in the buffer */
-                count = tty_buffer_request_room(tty, sci_rxfill(port));
+                count = tty_buffer_request_room(tport, sci_rxfill(port));
 
                 /* If for any reason we can't copy more data, we're done! */
                 if (count == 0)
@@ -1263,9 +1264,10 @@ static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty,
                            size_t count)
 {
         struct uart_port *port = &s->port;
+        struct tty_port *tport = &port->state->port;
         int i, active, room;
 
-        room = tty_buffer_request_room(tty, count);
+        room = tty_buffer_request_room(tport, count);
 
         if (s->active_rx == s->cookie_rx[0]) {
                 active = 0;
diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index f99b0c965f85..ed047d9ab1e2 100644
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -469,7 +469,8 @@ static void qe_uart_int_rx(struct uart_qe_port *qe_port)
         int i;
         unsigned char ch, *cp;
         struct uart_port *port = &qe_port->port;
-        struct tty_struct *tty = port->state->port.tty;
+        struct tty_port *tport = &port->state->port;
+        struct tty_struct *tty = tport->tty;
         struct qe_bd *bdp;
         u16 status;
         unsigned int flg;
@@ -491,7 +492,7 @@ static void qe_uart_int_rx(struct uart_qe_port *qe_port)
                 /* If we don't have enough room in RX buffer for the entire BD,
                  * then we try later, which will be the next RX interrupt.
                  */
-                if (tty_buffer_request_room(tty, i) < i) {
+                if (tty_buffer_request_room(tport, i) < i) {
                         dev_dbg(port->dev, "ucc-uart: no room in RX buffer\n");
                         return;
                 }
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 45d916198f78..f897332fb4ee 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -235,7 +235,7 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size)
 
 /**
  *      tty_buffer_request_room         -       grow tty buffer if needed
- *      @tty: tty structure
+ *      @port: tty port structure
  *      @size: size desired
  *
  *      Make at least size bytes of linear space available for the tty
@@ -243,9 +243,8 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size)
  *
  *      Locking: Takes port->buf.lock
  */
-int tty_buffer_request_room(struct tty_struct *tty, size_t size)
+int tty_buffer_request_room(struct tty_port *port, size_t size)
 {
-        struct tty_port *port = tty->port;
         unsigned long flags;
         int length;
 
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c
index d152be97d041..1e67fd89e346 100644
--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -697,7 +697,7 @@ void qt2_process_read_urb(struct urb *urb)
                                 escapeflag = true;
                                 break;
                         case QT2_CONTROL_ESCAPE:
-                                tty_buffer_request_room(tty, 2);
+                                tty_buffer_request_room(&port->port, 2);
                                 tty_insert_flip_string(tty, ch, 2);
                                 i += 2;
                                 escapeflag = true;
@@ -713,7 +713,7 @@ void qt2_process_read_urb(struct urb *urb)
                 }
 
                 if (tty) {
-                        tty_buffer_request_room(tty, 1);
+                        tty_buffer_request_room(&port->port, 1);
                         tty_insert_flip_string(tty, ch, 1);
                 }
         }
diff --git a/include/linux/tty_flip.h b/include/linux/tty_flip.h
index 2002344ed36a..78207ca8fab1 100644
--- a/include/linux/tty_flip.h
+++ b/include/linux/tty_flip.h
@@ -1,7 +1,7 @@
 #ifndef _LINUX_TTY_FLIP_H
 #define _LINUX_TTY_FLIP_H
 
-extern int tty_buffer_request_room(struct tty_struct *tty, size_t size);
+extern int tty_buffer_request_room(struct tty_port *port, size_t size);
 extern int tty_insert_flip_string_flags(struct tty_struct *tty, const unsigned char *chars, const char *flags, size_t size);
 extern int tty_insert_flip_string_fixed_flag(struct tty_struct *tty, const unsigned char *chars, char flag, size_t size);
 extern int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size);