lkml.org 
[lkml]   [2007]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: suspend/hibernation regression between 2.6.19 and 2.6.20 w/ Thinkpad T41
Date
On Monday, 6 August 2007 16:36, Henrique de Moraes Holschuh wrote:
> On Mon, 06 Aug 2007, Toralf Förster wrote:
> > Am Montag, 6. August 2007 00:29 schrieb Pavel Machek:
> > > Yes, I seen similar reports. Does it happen in all shutdown mode and
> > > 2.6.22? Does it happen in platform mode in 2.6.19?
> >
> > I can reproduce this behaviour by doing the following with kernel 2.6.20 :
> >
> > 1. <Fn>+<F4> - the systems sleeps within RAM
> > 2. <Fn> - the systems wakes up
> > 3. <Fn>+<F12> - the systems hibernates to disk
> > 4. <power> - systems wakes up
> > 5. <Fn>+<F4> - the systems sleeps within RAM
> >
> > Now pressing <Fn> doesn't wake up the system, I have to press the power button
> > for that instead.
>
> The resume path for suspend to disk is very different (for the firmware, at
> least) than the resume path from sleep-to-RAM. One of them goes through a
> system shutdown and cold boot (S5) or whatever-boot (S4 - who knows if it is
> the same as a cold boot in a given thinkpad model? It doesn't have to be!).
>
> The firmware *knows* when you press Fn+F4/FN+F12, and recalls that. That's
> why you can't get multiple hot key presses from pressing Fn+F4 or FN+F12
> until you actually do an ACPI wake-up.
>
> While you are just doing S3, all that state is preserved without fuss. But
> S5 does not preserve anything, and S4 is anyone's guess. Numerous thinkpad
> BIOS fixes in the past were releated to such problems, so if you are not
> using the latest BIOS for your model, your first duty is to upgrade it and
> try again.
>
> IMHO, probably some ACPI state is being lost by the BIOS because of the
> sleep-to-disk. I don't know how sleep-to-disk plays with the ACPI NV areas,
> and ACPI data areas from the BIOS, so I can't help much there.

We have the problem that ACPI is already initialized by the boot kernel before
the hibernation image is loaded, so there's a chance that the saved state
information will be lost.

Greetings,
Rafael


--
"Premature optimization is the root of all evil." - Donald Knuth
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-08-06 16:49    [W:0.152 / U:0.200 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site