1 files changed, 21 insertions, 12 deletions

diff --git a/drivers/char/n_r3964.c b/drivers/char/n_r3964.c
index 6b918b80f73e..902169062332 100644
--- a/drivers/char/n_r3964.c
+++ b/drivers/char/n_r3964.c
@@ -376,8 +376,9 @@ static void put_char(struct r3964_info *pInfo, unsigned char ch)
 	if (tty == NULL)
 		return;
 
-	if (tty->driver->put_char) {
-		tty->driver->put_char(tty, ch);
+	/* FIXME: put_char should not be called from an IRQ */
+	if (tty->ops->put_char) {
+		tty->ops->put_char(tty, ch);
 	}
 	pInfo->bcc ^= ch;
 }
@@ -386,12 +387,9 @@ static void flush(struct r3964_info *pInfo)
 {
 	struct tty_struct *tty = pInfo->tty;
 
-	if (tty == NULL)
+	if (tty == NULL || tty->ops->flush_chars == NULL)
 		return;
-
-	if (tty->driver->flush_chars) {
-		tty->driver->flush_chars(tty);
-	}
+	tty->ops->flush_chars(tty);
 }
 
 static void trigger_transmit(struct r3964_info *pInfo)
@@ -449,12 +447,11 @@ static void transmit_block(struct r3964_info *pInfo)
 	struct r3964_block_header *pBlock = pInfo->tx_first;
 	int room = 0;
 
-	if ((tty == NULL) || (pBlock == NULL)) {
+	if (tty == NULL || pBlock == NULL) {
 		return;
 	}
 
-	if (tty->driver->write_room)
-		room = tty->driver->write_room(tty);
+	room = tty_write_room(tty);
 
 	TRACE_PS("transmit_block %p, room %d, length %d",
 		 pBlock, room, pBlock->length);
@@ -1075,12 +1072,15 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
 
 	TRACE_L("read()");
 
+	lock_kernel();
+
 	pClient = findClient(pInfo, task_pid(current));
 	if (pClient) {
 		pMsg = remove_msg(pInfo, pClient);
 		if (pMsg == NULL) {
 			/* no messages available. */
 			if (file->f_flags & O_NONBLOCK) {
+				unlock_kernel();
 				return -EAGAIN;
 			}
 			/* block until there is a message: */
@@ -1090,8 +1090,10 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
 
 		/* If we still haven't got a message, we must have been signalled */
 
-		if (!pMsg)
+		if (!pMsg) {
+			unlock_kernel();
 			return -EINTR;
+		}
 
 		/* deliver msg to client process: */
 		theMsg.msg_id = pMsg->msg_id;
@@ -1102,12 +1104,15 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
 		kfree(pMsg);
 		TRACE_M("r3964_read - msg kfree %p", pMsg);
 
-		if (copy_to_user(buf, &theMsg, count))
+		if (copy_to_user(buf, &theMsg, count)) {
+			unlock_kernel();
 			return -EFAULT;
+		}
 
 		TRACE_PS("read - return %d", count);
 		return count;
 	}
+	unlock_kernel();
 	return -EPERM;
 }
 
@@ -1156,6 +1161,8 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
 	pHeader->locks = 0;
 	pHeader->owner = NULL;
 
+	lock_kernel();
+
 	pClient = findClient(pInfo, task_pid(current));
 	if (pClient) {
 		pHeader->owner = pClient;
@@ -1173,6 +1180,8 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
 	add_tx_queue(pInfo, pHeader);
 	trigger_transmit(pInfo);
 
+	unlock_kernel();
+
 	return 0;
 }