n_tty: Eliminate counter in __process_echoes

Since neither echo_commit nor echo_tail can change for the duration
of __process_echoes loop, substitute index comparison for the
snapshot counter.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 59f3f10f37f3236e1b5c41eb40815a59a764dfdf..7f15b269cf3ef3ca2bdf723b65fdcfcaf23160bb 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -656,8 +656,7 @@ static size_t __process_echoes(struct tty_struct *tty)
        old_space = space = tty_write_room(tty);
 
        tail = ldata->echo_tail;
-       nr = ldata->echo_commit - ldata->echo_tail;
-       while (nr > 0) {
+       while (ldata->echo_commit != tail) {
                c = echo_buf(ldata, tail);
                if (c == ECHO_OP_START) {
                        unsigned char op;
@@ -701,20 +700,17 @@ static size_t __process_echoes(struct tty_struct *tty)
                                                ldata->column--;
                                }
                                tail += 3;
-                               nr -= 3;
                                break;
 
                        case ECHO_OP_SET_CANON_COL:
                                ldata->canon_column = ldata->column;
                                tail += 2;
-                               nr -= 2;
                                break;
 
                        case ECHO_OP_MOVE_BACK_COL:
                                if (ldata->column > 0)
                                        ldata->column--;
                                tail += 2;
-                               nr -= 2;
                                break;
 
                        case ECHO_OP_START:
@@ -727,7 +723,6 @@ static size_t __process_echoes(struct tty_struct *tty)
                                ldata->column++;
                                space--;
                                tail += 2;
-                               nr -= 2;
                                break;
 
                        default:
@@ -749,7 +744,6 @@ static size_t __process_echoes(struct tty_struct *tty)
                                ldata->column += 2;
                                space -= 2;
                                tail += 2;
-                               nr -= 2;
                        }
 
                        if (no_space_left)
@@ -767,7 +761,6 @@ static size_t __process_echoes(struct tty_struct *tty)
                                space -= 1;
                        }
                        tail += 1;
-                       nr -= 1;
                }
        }