Re: [linux-pm] [PATCH 0/8] Suspend block api (version 6)

[Kevin Hilman]

Magnus Damm <magnus.damm@xxxxxxxxx> writes:

> Still not sure how the system wide suspend is different from Runtime
> PM and CPUidle from the hardware perspective...

At least on OMAP and other embedded SoCs I'm familiar with, there is
no difference from the hardware perspecitve.

However, I understand that on ACPI-based systems, there are low-power
that are only reachable via system-wide suspsend since ACPI does not
provide the kernel with fine-grained control to hit those states
during idle.

That being said, I don't think this should be an issue since
opportunistic suspend is currently targetted primarily at embedded HW
which has much more fine-grained power control than traditional
ACPI-based systems.

To me the only real difference between system-wide suspend and runtime
PM + CPUidle is the freezing of userspace.

As has been discussed elsewhere in this discussion, any alternative
solution must address the freezing/idling of userspace.  

Kevin
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/