Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4b4ecd9c authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Greg Kroah-Hartman
Browse files

vt: Perform safe console erase only once 



Commit f8df13e0 ("tty: Clean console safely") added code to clear
both the scrollback buffer and the screen with "\e[3J", then execution
falls through into the code to simply clear the screen. This means
scr_memsetw() and the console driver update callback are called twice
on the whole screen buffer. Let's reorganize the code so the same work
is not performed twice needlessly.

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 339c7a87

drivers/tty/vt/vt.c

+7 −9
Original line number Diff line number Diff line
@@ -1178,15 +1178,8 @@ static void csi_J(struct vc_data *vc, int vpar) 
			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;

			start = (unsigned short *)vc->vc_origin;

			break;

		case 3: /* erase scroll-back buffer (and whole display) */

			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,

				    vc->vc_screenbuf_size);

			flush_scrollback(vc);

			set_origin(vc);

			if (con_is_visible(vc))

				update_screen(vc);

			/* fall through */

		case 2: /* erase whole display */

		case 3: /* (and scrollback buffer later) */

			count = vc->vc_cols * vc->vc_rows;

			start = (unsigned short *)vc->vc_origin;

			break;
@@ -1194,7 +1187,12 @@ static void csi_J(struct vc_data *vc, int vpar) 
			return;

	}

	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);

	if (con_should_update(vc))

	if (vpar == 3) {

		set_origin(vc);

		flush_scrollback(vc);

		if (con_is_visible(vc))

			update_screen(vc);

	} else if (con_should_update(vc))

		do_update_region(vc, (unsigned long) start, count);

	vc->vc_need_wrap = 0;

}