On Wed, 29 Dec 2004, Ed Hill wrote:
> On Wed, 2004-12-29 at 08:48 -1000, Amy M wrote:
> > All things considered, this fedora-list has become perhaps one of the
> > best forums to learn Linux. Our sincere thanks to those who are
> > gracious enough to donate their time answering questions that sometimes
> > may seem ridiculous.
> >
> > My question now is: From what I have read, it appears that if I want to
> > do suspend to ram, I have to forgo acpi and use apm. Performance-wise,
> > would anyone care to comment on the pros and cons of acpi vis-a-vis
> > apm? Thanks again.
Definitely system-dependent. Try www.linux-on-laptops.com to see what
others have experienced.
>
> Hi Amy,
>
> I can only relate my FC kernel-2.6 experiences for one laptop, a
> ThinkPad A22p (PIII-900) and they are:
>
> - with very recent kernels (eg. 2.6.9-1.681_FC3) both APM
> and ACPI suspend-to-RAM work
> - with both I often need to unload and then re-load the
> sound kernel modules
> - APM:
> - uses *very* little power when suspended to RAM (lasts
> for many days starting from a full charge)
> - can occasionally have problems with pcmcia (even when
> all cards are removed) so I usually use:
> "/etc/init.d/pcmcia stop ; apm -s"
> and then restart pcmcia after wake-up with:
> "/etc/init.d/pcmcia start"
- Cycles my miniPCI wireless card, so that resuming puts me on the
network where I am, even if I've changed location.
> - results in lockups about once every 40--50 suspend-
> resume cycles
> - ACPI:
> - has no apparent problems with pcmcia
> - experienced no lockups (in about ~60 cycles)
> - uses a *LOT* (perhaps as much as 10X) more battery
> power while suspended to RAM
Known bug affecing Thinkpads. See Red Hat Bugzilla 142928, which points
to http://bugzilla.kernel.org/show_bug.cgi?id=3022. Other systems may not
be affected to this extent.
> - suspends and resumes very quickly
> - routinely gives a kernel error on wakeup saying
> something about interruptable_sleep() but they seem
> to be harmless
- Does not restart my miniPCI network card.
>
> Having done many hundreds of suspend-resume cycles using both APM and
> ACPI, I've decided to stick with APM to reduce the battery usage.
Me too (Thinkpad T41), but I'm hoping to see the fix sometime soon. The
suspend/resume cycle is much faster with ACPI.
>
> Ed
>
>
--
Matthew Saltzman
Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs
