linux-kernel - [PATCH linux-next V2] tty: Disable default console blanking interval

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 22 Mar 2017 09:07:20 -0600
From:   Tim Gardner <tim.gardner@...onical.com>
To:     linux-kernel@...r.kernel.org
Cc:     Tim Gardner <tim.gardner@...onical.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jslaby@...e.com>,
        Adam Borowski <kilobyte@...band.pl>,
        Scot Doyle <lkml14@...tdoyle.com>
Subject: [PATCH linux-next V2] tty: Disable default console blanking interval

BugLink: http://bugs.launchpad.net/bugs/869017

Console blanking is not enabling DPMS power saving (thereby negating any
power-saving benefit), and is simply turning the screen content blank. This
means that any crash output is invisible which is unhelpful on a server
(virtual or otherwise).

Furthermore, CRT burn in concerns should no longer govern the default case.
Affected users could always set consoleblank on the kernel command line.

Signed-off-by: Tim Gardner <tim.gardner@...onical.com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Jiri Slaby <jslaby@...e.com>
Cc: Adam Borowski <kilobyte@...band.pl>
Cc: Scot Doyle <lkml14@...tdoyle.com>
---

I'm not particularly knowledgable about console issues. Is a blaknking interval
relevant in a post CRT world ? The argument in the bug description seems
compelling.

V2 - expanded commit log with relevant context.

 drivers/tty/vt/vt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 5c4933b..9c99452 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -181,7 +181,7 @@ int console_blanked;

 static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
 static int vesa_off_interval;
-static int blankinterval = 10*60;
+static int blankinterval;
 core_param(consoleblank, blankinterval, int, 0444);

 static DECLARE_WORK(console_work, console_callback);
-- 
2.7.4