Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: suspend/hibernation regression between 2.6.19 and 2.6.20 w/ Thinkpad T41 | Date | Mon, 6 Aug 2007 16:56:16 +0200 |
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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
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