screen dead after resume on Thinkpad X30

[Ian Smith]

On Thu, 7 Dec 2006, Nate Lawson wrote:
 > Ian Smith wrote:
 > > On Thu, 7 Dec 2006, Lutz Boehne wrote:
 > > 
 > >  > I'm tracking RELENG_6 and after one upgrade, my Thinkpad X30 does not
 > >  > properly wake up out of standby anymore. After waking up, the laptop
 > >  > will still respond to key presses and I am able to reboot it by pressing
 > >  > Ctrl-Alt-Del, but nothing will appear on the screen until I see the BIOS
 > >  > POST.
 > >  > 
 > >  > I spent some time to narrow down which changes in RELENG_6 seem to be
 > >  > responsible and found out that RELENG_6 from August 16th 2006 12:01am
 > >  > works fine and that RELENG_6 from 08:00pm that day does not.
 > >  > 
 > >  > Candidate files are:
 > >  > src/sys/dev/acpica/acpi_video.c
 > >  > src/sys/i386/acpica/acpi_machdep.c
 > >  > src/sys/i386/acpica/acpi_wakecode.S
 > >  > src/sys/i386/acpica/acpi_wakeup.c
 > >  > 
 > >  > I locally replaced those files in today's RELENG_6 with versions from
 > >  > before August 16th, built/installed kernel and world and resume works
 > >  > properly again.
 > > 
 > > Not sure if it's your {,only} problem, but the default value for
 > > hw.acpi.reset_video changed fairly recently, I think from 1 to 0, as I
 > > had to set hw.acpi.reset_video=0 in /etc/sysctl.conf on a Thinkpad T23
 > > on 6.1-RELEASE.  You'll find recent references to this in the archives. 
 > > 
 > > Try hardwiring the value from your working version into sysctl.conf.
 > > 
 > > FWIW, I also needed hw.syscons.sc_no_suspend_vtswitch=1 on the T23.
 > 
 > Thanks for answering.  The reason why the default is now 0 is that it 
 > caused some systems to spontaneously reset if it was 1.  I did a quick 
 > check and it seemed that 1 causes more trouble overall than 0 so 0 is 
 > the default.

Fair enough too .. but since this is likely to catch a few more folks
unawares, do you think it may be worth a mention in /usr/src/UPDATING?

Cheers, Ian