Re: vt: regression caused by "Fix line garbage in virtual.."

[Krzysztof Mazur]

On Mon, Nov 19, 2012 at 08:21:49PM +0100, Jean-Francois Moine wrote:
> On Mon, 19 Nov 2012 11:38:28 +0000
> Alan Cox <alan@xxxxxxxxxxxxxxx> wrote:
> 
> > > There are some garbage after mousedev.c not present on older kernels.
> > > 
> > > Reverting commit 81732c in v3.7-rc6 fixes the issue.
> > 
> > Then we should drop this for 3.7 until a fixed one is provided IMHO.
> > Its not relevant to most platforms.
> 
> Sorry, juggling with the byte offsets and the character indexes was not
> so obvious.

That's why I even did not try to fix it.

> 
> Here is a patch towards the kernel 3.7.
> 
> Krzysztof, may you check it?
>

That patch fixed the original issue, but I noticed another artifact
(I tested only v3.7-rc6 after your fix, I didn't check if the same
problems exists in v3.7).

After:

for ((i = 0; i < 40; i++)); do
	echo "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
done
echo -e -n "\x0d\x1b[2@"

(also generated by bash during command line editing, this time by CTRL-r
+ something)

the first character on screen (first column and first row) is cleared.


I think it's too late for fixing it in 3.7 and it's better, like Alan
proposed, to just revert it for now.

Thanks,

Krzysiek
-- >8 --
Subject: [PATCH] Revert "tty vt: Fix line garbage in virtual console on
 command line edition"

This reverts commit 81732c3b2fede049a692e58a7ceabb6d18ffb18c.

This commit introduced frequent display artifacts during simple
command line editing in bash, at least with framebuffer
console on top inteldrmfb and radeondrmfb framebuffers.

Signed-off-by: Krzysztof Mazur <krzysiek@xxxxxxxxxxxx>
---
 drivers/tty/vt/vt.c | 78 +++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 61 insertions(+), 17 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index f87d7e8..3e89dba 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -537,27 +537,45 @@ void complement_pos(struct vc_data *vc, int offset)
 
 static void insert_char(struct vc_data *vc, unsigned int nr)
 {
-	unsigned short *p = (unsigned short *) vc->vc_pos;
+	unsigned short *p, *q = (unsigned short *)vc->vc_pos;
 
-	scr_memmovew(p + nr, p, vc->vc_cols - vc->vc_x);
-	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
+	p = q + vc->vc_cols - nr - vc->vc_x;
+	while (--p >= q)
+		scr_writew(scr_readw(p), p + nr);
+	scr_memsetw(q, vc->vc_video_erase_char, nr * 2);
 	vc->vc_need_wrap = 0;
-	if (DO_UPDATE(vc))
-		do_update_region(vc, (unsigned long) p,
-			(vc->vc_cols - vc->vc_x) / 2 + 1);
+	if (DO_UPDATE(vc)) {
+		unsigned short oldattr = vc->vc_attr;
+		vc->vc_sw->con_bmove(vc, vc->vc_y, vc->vc_x, vc->vc_y, vc->vc_x + nr, 1,
+				     vc->vc_cols - vc->vc_x - nr);
+		vc->vc_attr = vc->vc_video_erase_char >> 8;
+		while (nr--)
+			vc->vc_sw->con_putc(vc, vc->vc_video_erase_char, vc->vc_y, vc->vc_x + nr);
+		vc->vc_attr = oldattr;
+	}
 }
 
 static void delete_char(struct vc_data *vc, unsigned int nr)
 {
-	unsigned short *p = (unsigned short *) vc->vc_pos;
+	unsigned int i = vc->vc_x;
+	unsigned short *p = (unsigned short *)vc->vc_pos;
 
-	scr_memcpyw(p, p + nr, vc->vc_cols - vc->vc_x - nr);
-	scr_memsetw(p + vc->vc_cols - vc->vc_x - nr, vc->vc_video_erase_char,
-			nr * 2);
+	while (++i <= vc->vc_cols - nr) {
+		scr_writew(scr_readw(p+nr), p);
+		p++;
+	}
+	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
 	vc->vc_need_wrap = 0;
-	if (DO_UPDATE(vc))
-		do_update_region(vc, (unsigned long) p,
-			(vc->vc_cols - vc->vc_x) / 2);
+	if (DO_UPDATE(vc)) {
+		unsigned short oldattr = vc->vc_attr;
+		vc->vc_sw->con_bmove(vc, vc->vc_y, vc->vc_x + nr, vc->vc_y, vc->vc_x, 1,
+				     vc->vc_cols - vc->vc_x - nr);
+		vc->vc_attr = vc->vc_video_erase_char >> 8;
+		while (nr--)
+			vc->vc_sw->con_putc(vc, vc->vc_video_erase_char, vc->vc_y,
+				     vc->vc_cols - 1 - nr);
+		vc->vc_attr = oldattr;
+	}
 }
 
 static int softcursor_original;
@@ -1154,26 +1172,45 @@ static void csi_J(struct vc_data *vc, int vpar)
 		case 0:	/* erase from cursor to end of display */
 			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
 			start = (unsigned short *)vc->vc_pos;
+			if (DO_UPDATE(vc)) {
+				/* do in two stages */
+				vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1,
+					      vc->vc_cols - vc->vc_x);
+				vc->vc_sw->con_clear(vc, vc->vc_y + 1, 0,
+					      vc->vc_rows - vc->vc_y - 1,
+					      vc->vc_cols);
+			}
 			break;
 		case 1:	/* erase from start to cursor */
 			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
 			start = (unsigned short *)vc->vc_origin;
+			if (DO_UPDATE(vc)) {
+				/* do in two stages */
+				vc->vc_sw->con_clear(vc, 0, 0, vc->vc_y,
+					      vc->vc_cols);
+				vc->vc_sw->con_clear(vc, vc->vc_y, 0, 1,
+					      vc->vc_x + 1);
+			}
 			break;
 		case 3: /* erase scroll-back buffer (and whole display) */
 			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
 				    vc->vc_screenbuf_size >> 1);
 			set_origin(vc);
+			if (CON_IS_VISIBLE(vc))
+				update_screen(vc);
 			/* fall through */
 		case 2: /* erase whole display */
 			count = vc->vc_cols * vc->vc_rows;
 			start = (unsigned short *)vc->vc_origin;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, 0, 0,
+					      vc->vc_rows,
+					      vc->vc_cols);
 			break;
 		default:
 			return;
 	}
 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
-	if (DO_UPDATE(vc))
-		do_update_region(vc, (unsigned long) start, count);
 	vc->vc_need_wrap = 0;
 }
 
@@ -1186,22 +1223,29 @@ static void csi_K(struct vc_data *vc, int vpar)
 		case 0:	/* erase from cursor to end of line */
 			count = vc->vc_cols - vc->vc_x;
 			start = (unsigned short *)vc->vc_pos;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1,
+						     vc->vc_cols - vc->vc_x);
 			break;
 		case 1:	/* erase from start of line to cursor */
 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
 			count = vc->vc_x + 1;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, vc->vc_y, 0, 1,
+						     vc->vc_x + 1);
 			break;
 		case 2: /* erase whole line */
 			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
 			count = vc->vc_cols;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, vc->vc_y, 0, 1,
+					      vc->vc_cols);
 			break;
 		default:
 			return;
 	}
 	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
 	vc->vc_need_wrap = 0;
-	if (DO_UPDATE(vc))
-		do_update_region(vc, (unsigned long) start, count);
 }
 
 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
-- 
1.8.0.283.gc57d856

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