Red Hat Bugzilla – Bug 233761
Failure to suspend on PowerBook
Last modified: 2015-03-04 20:18:30 EST
/usr/sbin/pm-suspend fails on my PowerBook, with the following complaint:
Error: kernel cannot suspend to ram.
Commenting out the offending check makes it work, since it talks to the PMU
Really? That's it? I had assumed the kernel actually wasn't capable of
suspending to RAM on PMU-using machines.
The check you're referring to, I assume, is this:
if ! grep -q mem /sys/power/state ; then
echo "Error: kernel cannot suspend to ram." 1>&2
Is there an equivalent sysfs file for PMU state/capabilities? Maybe the kernel
needs a simple patch to export the PMU info in /sys/power/state?
The kernel has been suspending to RAM on PMU-based machines for _much_ longer
than it's been doing so with ACPI crap.
There is work afoot to make the kernel suspend/resume using the "generic" stuff
in /sys/power/state, but it isn't yet ready -- it isn't just a simple patch,
because that "generic" code was fairly poorly-designed.
I don't believe there's a sysfs file you can query to check if the machine can
suspend. Trust HAL; it has a special case.
Actually I have some working patches which make /sys/power/state work. I'll look
at putting them into the rawhide kernel.
The kernel now lets you use /sys/power/state.