1 files changed, 40 insertions, 39 deletions

diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index 4e28b35024ec..2e50f4dfc79c 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -272,7 +272,8 @@ static inline int is_continuation(unsigned char c, struct tty_struct *tty)
  *
  *      This is a helper function that handles one output character
  *      (including special characters like TAB, CR, LF, etc.),
- *      putting the results in the tty driver's write buffer.
+ *      doing OPOST processing and putting the results in the
+ *      tty driver's write buffer.
  *
  *      Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
  *      and NLDLY.  They simply aren't relevant in the world today.
@@ -350,8 +351,9 @@ static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
  *      @c: character (or partial unicode symbol)
  *      @tty: terminal device
  *
- *      Perform OPOST processing.  Returns -1 when the output device is
- *      full and the character must be retried.
+ *      Output one character with OPOST processing.
+ *      Returns -1 when the output device is full and the character
+ *      must be retried.
  *
  *      Locking: output_lock to protect column state and space left
  *               (also, this is called from n_tty_write under the
@@ -377,8 +379,11 @@ static int process_output(unsigned char c, struct tty_struct *tty)
 /**
  *      process_output_block            -       block post processor
  *      @tty: terminal device
- *      @inbuf: user buffer
- *      @nr: number of bytes
+ *      @buf: character buffer
+ *      @nr: number of bytes to output
+ *
+ *      Output a block of characters with OPOST processing.
+ *      Returns the number of characters output.
  *
  *      This path is used to speed up block console writes, among other
  *      things when processing blocks of output data. It handles only
@@ -571,33 +576,23 @@ static void process_echoes(struct tty_struct *tty)
                                 break;
 
                         default:
-                                if (iscntrl(op)) {
-                                        if (L_ECHOCTL(tty)) {
-                                                /*
-                                                 * Ensure there is enough space
-                                                 * for the whole ctrl pair.
-                                                 */
-                                                if (space < 2) {
-                                                        no_space_left = 1;
-                                                        break;
-                                                }
-                                                tty_put_char(tty, '^');
-                                                tty_put_char(tty, op ^ 0100);
-                                                tty->column += 2;
-                                                space -= 2;
-                                        } else {
-                                                if (!space) {
-                                                        no_space_left = 1;
-                                                        break;
-                                                }
-                                                tty_put_char(tty, op);
-                                                space--;
-                                        }
-                                }
                                 /*
-                                 * If above falls through, this was an
-                                 * undefined op.
+                                 * If the op is not a special byte code,
+                                 * it is a ctrl char tagged to be echoed
+                                 * as "^X" (where X is the letter
+                                 * representing the control char).
+                                 * Note that we must ensure there is
+                                 * enough space for the whole ctrl pair.
+                                 *
                                  */
+                                if (space < 2) {
+                                        no_space_left = 1;
+                                        break;
+                                }
+                                tty_put_char(tty, '^');
+                                tty_put_char(tty, op ^ 0100);
+                                tty->column += 2;
+                                space -= 2;
                                 cp += 2;
                                 nr -= 2;
                         }
@@ -605,12 +600,18 @@ static void process_echoes(struct tty_struct *tty)
                         if (no_space_left)
                                 break;
                 } else {
-                        int retval;
-
-                        retval = do_output_char(c, tty, space);
-                        if (retval < 0)
-                                break;
-                        space -= retval;
+                        if (O_OPOST(tty) &&
+                            !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
+                                int retval = do_output_char(c, tty, space);
+                                if (retval < 0)
+                                        break;
+                                space -= retval;
+                        } else {
+                                if (!space)
+                                        break;
+                                tty_put_char(tty, c);
+                                space -= 1;
+                        }
                         cp += 1;
                         nr -= 1;
                 }
@@ -798,8 +799,8 @@ static void echo_char_raw(unsigned char c, struct tty_struct *tty)
  *      Echo user input back onto the screen. This must be called only when
  *      L_ECHO(tty) is true. Called from the driver receive_buf path.
  *
- *      This variant tags control characters to be possibly echoed as
- *      as "^X" (where X is the letter representing the control char).
+ *      This variant tags control characters to be echoed as "^X"
+ *      (where X is the letter representing the control char).
  *
  *      Locking: echo_lock to protect the echo buffer
  */
@@ -812,7 +813,7 @@ static void echo_char(unsigned char c, struct tty_struct *tty)
                 add_echo_byte(ECHO_OP_START, tty);
                 add_echo_byte(ECHO_OP_START, tty);
         } else {
-                if (iscntrl(c) && c != '\t')
+                if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t')
                         add_echo_byte(ECHO_OP_START, tty);
                 add_echo_byte(c, tty);
         }