console: make blank timeout value a boot option
The console blank timer is currently hardcoded to 10*60 seconds which
might be annoying on systems with no input devices attached to wake up the
console again. Especially during development, disabling the screen saver
can be handy - for example when debugging the root fs mount mechanism or
other scenarios where no userspace program could be started to do that at
runtime from userspace.
This patch defines a core_param for the variable in charge which allows
users to entirely disable the blank feature at boot time by setting it 0.
The value can still be overwritten at runtime using the standard ioctl
call - this just allows to conditionally change the default.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index ad38006..5578248 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -546,6 +546,10 @@
console=brl,ttyS0
For now, only VisioBraille is supported.
+ consoleblank= [KNL] The console blank (screen saver) timeout in
+ seconds. Defaults to 10*60 = 10mins. A value of 0
+ disables the blank timer.
+
coredump_filter=
[KNL] Change the default value for
/proc/<pid>/coredump_filter.
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index c796a86..d9113b4 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -171,8 +171,9 @@
int console_blanked;
static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
-static int blankinterval = 10*60*HZ;
static int vesa_off_interval;
+static int blankinterval = 10*60;
+core_param(consoleblank, blankinterval, int, 0444);
static DECLARE_WORK(console_work, console_callback);
@@ -1485,7 +1486,7 @@
update_attr(vc);
break;
case 9: /* set blanking interval */
- blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
+ blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
poke_blanked_console();
break;
case 10: /* set bell frequency in Hz */
@@ -2871,7 +2872,7 @@
if (blankinterval) {
blank_state = blank_normal_wait;
- mod_timer(&console_timer, jiffies + blankinterval);
+ mod_timer(&console_timer, jiffies + (blankinterval * HZ));
}
for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
@@ -3677,7 +3678,7 @@
return; /* but leave console_blanked != 0 */
if (blankinterval) {
- mod_timer(&console_timer, jiffies + blankinterval);
+ mod_timer(&console_timer, jiffies + (blankinterval * HZ));
blank_state = blank_normal_wait;
}
@@ -3711,7 +3712,7 @@
static void blank_screen_t(unsigned long dummy)
{
if (unlikely(!keventd_up())) {
- mod_timer(&console_timer, jiffies + blankinterval);
+ mod_timer(&console_timer, jiffies + (blankinterval * HZ));
return;
}
blank_timer_expired = 1;
@@ -3741,7 +3742,7 @@
if (console_blanked)
unblank_screen();
else if (blankinterval) {
- mod_timer(&console_timer, jiffies + blankinterval);
+ mod_timer(&console_timer, jiffies + (blankinterval * HZ));
blank_state = blank_normal_wait;
}
}