Subject: Re: Call for testers: i386 ACPI suspend/resume support
To: Perry E. Metzger <email@example.com>
From: Steven M. Bellovin <firstname.lastname@example.org>
Date: 06/20/2006 22:38:51
On Tue, 20 Jun 2006 22:26:41 -0400, "Perry E. Metzger"
> "Steven M. Bellovin" <email@example.com> writes:
> > When I'm in X and suspend, on resume I see a blank screen with a blinking
> > VGA-type cursor in the upper left. I can restore my X by switching
> > consoles away from screen 5 and then back.
> This is not surprising. S3 is allowed to power off *everything* but
> memory, so the state of the video chip is lost. On restore we do a
> reset of the video, but we don't know what the state of the chip was
> before sleep. X effectively manages the drivers entirely in userland,
> so unless X decides to re-initialize the display it is going to be
> screwed up.
> One thing we can do, though, is use the same protocol that is used
> when we switch from a particular vt console back to X to tell the X
> server to take control back of the screen.
I think that that's the right thing to do.
> > Speedstep, via estd, is *not* working; the speed stays at 1800 Mhz.
> I think that's handled by the same chip that handles the USB stuff --
> we're failing to re-initialize it properly.
Oddly enough, I can't reproduce that problem. I did update userland in
between; maybe that helped (though my userland had been reasonably up to
date). Nor can I reproduce the problem of strange lines on my screen.
At this point, the sole issue keeping me from running this full-time,
rather than apm, is USB.
--Steven M. Bellovin, http://www.cs.columbia.edu/~smb