Bug 233356

Summary:	vt(4) doesn't support rc.conf parameters saver= or blanktime=
Product:	Base System	Reporter:	Joe Barbish <qjail1>
Component:	kern	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	New ---
Severity:	Affects Many People	CC:	emaste, felix, guilherme.janczak, nickdate, scf
Priority:	---	Keywords:	vt
Version:	CURRENT
Hardware:	Any
OS:	Any
See Also:	https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=224436

Description Joe Barbish 2018-11-20 16:15:16 UTC

The vt default console screen driver doesn't support the rc.conf parameters saver=  or  blanktime=. The boot time console messages has this message,

Configuring vt: blanktime screensaver 

But really has no effect.

rc.conf contains saver="warp" & blanktime="900"

If kern.vty=sc in /boot/loader.conf then they work.

Comment 1 Joe Barbish 2018-11-20 16:21:22 UTC

Same effect in amd64 or i386 systems.

Comment 2 Ed Maste freebsd_committer

2019-09-16 19:18:04 UTC

blanktime needs CONS_BLANKTIME to be implemented:
https://github.com/freebsd/freebsd/blob/master/sys/dev/vt/vt_core.c#L2309

Comment 3 Ed Maste freebsd_committer

2024-05-24 22:17:39 UTC

Source code link has gone stale, it is supposed to be a link to the unimplemented CONS_BLANKTIME:

	case CONS_BLANKTIME:
		/* XXX */
		return (0);

Comment 4 Nick Date 2024-07-18 21:27:23 UTC

This issue is still present in 14.1-RELEASE. I spend  lot of time in the console without X running on my affected machine (it is a stationary laptop performing some server functions). I don't want to use sc because it doesn't work with KMS. Are there any plans to fix this?

Comment 5 Guilherme Janczak 2024-12-21 16:55:20 UTC

This bug caused burn-in on an old laptop I use via remote access. The FreeBSD login prompt was burned onto it after weeks/months continuously on and with the lid closed.

Setting kern.vty=sc in /boot/loader.conf caused the laptop to boot to a blank screen. sc's man page appears to warn against this on UEFI systems, but this laptop is BIOS.

A workaround is to start the xdm (X Display Manager) service on boot, closing the lid will then turn off the screen.