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path: root/drivers/char/n_tty.c
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Diffstat (limited to 'drivers/char/n_tty.c')
-rw-r--r--drivers/char/n_tty.c79
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);
}