tty: tty_buffer: use __tty_insert_flip_string_flags() in tty_insert_flip_char()

Use __tty_insert_flip_string_flags() for the slow path of
tty_insert_flip_char(). The former is generic enough, so there is no
reason to reimplement the injection once again.

So now we have a single function stuffing into tty buffers.

Signed-off-by: "Jiri Slaby (SUSE)" <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/driver-api/tty/tty_buffer.rst

···
 ======================
 
 .. kernel-doc:: drivers/tty/tty_buffer.c
-   :identifiers: tty_prepare_flip_string __tty_insert_flip_char
+   :identifiers: tty_prepare_flip_string
            tty_flip_buffer_push tty_ldisc_receive_buf
 
 .. kernel-doc:: include/linux/tty_flip.h
    :identifiers: tty_insert_flip_string_fixed_flag tty_insert_flip_string_flags
+           tty_insert_flip_char
 
 ----
 

drivers/tty/tty_buffer.c

···
 EXPORT_SYMBOL(__tty_insert_flip_string_flags);
 
 /**
- * __tty_insert_flip_char   -	add one character to the tty buffer
- * @port: tty port
- * @ch: character
- * @flag: flag byte
- *
- * Queue a single byte @ch to the tty buffering, with an optional flag. This is
- * the slow path of tty_insert_flip_char().
- */
-int __tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag)
-{
-	struct tty_buffer *tb;
-	bool flags = flag != TTY_NORMAL;
-
-	if (!__tty_buffer_request_room(port, 1, flags))
-		return 0;
-
-	tb = port->buf.tail;
-	if (tb->flags)
-		*flag_buf_ptr(tb, tb->used) = flag;
-	*char_buf_ptr(tb, tb->used++) = ch;
-
-	return 1;
-}
-EXPORT_SYMBOL(__tty_insert_flip_char);
-
-/**
  * tty_prepare_flip_string	-	make room for characters
  * @port: tty port
  * @chars: return pointer for character write area

include/linux/tty_flip.h

···
 				      size_t size);
 size_t tty_prepare_flip_string(struct tty_port *port, u8 **chars, size_t size);
 void tty_flip_buffer_push(struct tty_port *port);
-int __tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag);
 
 /**
  * tty_insert_flip_string_fixed_flag - add characters to the tty buffer
···
 	return __tty_insert_flip_string_flags(port, chars, flags, true, size);
 }
 
-
+/**
+ * tty_insert_flip_char - add one character to the tty buffer
+ * @port: tty port
+ * @ch: character
+ * @flag: flag byte
+ *
+ * Queue a single byte @ch to the tty buffering, with an optional flag.
+ */
 static inline size_t tty_insert_flip_char(struct tty_port *port, u8 ch, u8 flag)
 {
 	struct tty_buffer *tb = port->buf.tail;
···
 		*char_buf_ptr(tb, tb->used++) = ch;
 		return 1;
 	}
-	return __tty_insert_flip_char(port, ch, flag);
+	return __tty_insert_flip_string_flags(port, &ch, &flag, false, 1);
 }
 
 static inline size_t tty_insert_flip_string(struct tty_port *port,