linux-kernel - Re: [linux-pm] [PATCH] PM / i915: Skip kernel VT switch during suspend/resume if KMS is used

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]

Message-ID: <20100131085419.GI2238@elf.ucw.cz>
Date:	Sun, 31 Jan 2010 09:54:19 +0100
From:	Pavel Machek <pavel@....cz>
To:	Stefan Seyfried <stefan.seyfried@...glemail.com>
Cc:	"Rafael J. Wysocki" <rjw@...k.pl>, airlied@...ux.ie,
	LKML <linux-kernel@...r.kernel.org>,
	Jesse Barnes <jbarnes@...tuousgeek.org>,
	Eric Anholt <eric@...olt.net>,
	pm list <linux-pm@...ts.linux-foundation.org>,
	dri-devel@...ts.sourceforge.net,
	Alan Cox <alan@...rguk.ukuu.org.uk>
Subject: Re: [linux-pm] [PATCH] PM / i915: Skip kernel VT switch during
 suspend/resume	if KMS is used

On Thu 2010-01-28 00:07:51, Stefan Seyfried wrote:
> Hi,
> 
> On Tue, 26 Jan 2010 15:58:43 +0100 Pavel Machek <pavel@....cz> wrote:
> > We need vt switch when display is controlled by userland app directly
> > accessing hw. It may or may not be X (svgalib anyone?,
> > gtk-on-framebuffer? qtopia?).
> 
> anything-on-framebuffer should not be different from plain framebuffer
> console, or am I missing something?

It is. At least svgalib accesses hw directly. It probably can run even
on framebuffer.

> > Ideally, userspace should explicitely tell us. KD_KERNEL_GRAPHICS
> > console mode?
> > 
> > Plus the switch is needed for any graphics app using fbcon -- I do not
> > think we actually save the framebuffer over suspend. (This one should
> > probably be fixed).
> 
> Framebuffer should be easy to fix - it works pretty well already
> because apparently the fbcon code needs to "shadow buffer" all VT
> "windows" anyway - so maybe it's just the issue of doing an additional
> "redraw()" somewhere appropriate.

Well, for now the "shadow buffer" contains only text, not graphics
images. So you'd need to enlarge it a lot. Doable but more than one liner.

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/