[PATCH 22/38] vt: make tc write more obvious in vc_con_write_normal

From: Jiri Slaby
Date: Mon Jun 15 2020 - 03:50:45 EST


Nested ternary operators spread over 4 lines are really evil for
reading. Turn the outer one to proper 'if'. Now, we see, there is a
common path, so the code can be simplified. This way, the code is
understandable now.

Checked using symbolic execution (klee), that the old and new behaviors
are the same.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/tty/vt/vt.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 72ae8ede1ac9..4686f8b9251d 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2787,11 +2787,14 @@ static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
if (vc->vc_decim)
insert_char(vc, 1);
vc_uniscr_putc(vc, next_c);
- scr_writew(himask ?
- ((vc_attr << 8) & ~himask) +
- ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
- (vc_attr << 8) + tc,
- (u16 *)vc->vc_pos);
+
+ if (himask)
+ tc = ((tc & 0x100) ? himask : 0) |
+ (tc & 0xff);
+ tc |= (vc_attr << 8) & ~himask;
+
+ scr_writew(tc, (u16 *)vc->vc_pos);
+
if (con_should_update(vc) && draw->x < 0) {
draw->x = vc->state.x;
draw->from = vc->vc_pos;
--
2.27.0