[eepro100] Low power states in the 82559/82559ER chips

[Donald Becker]

On Thu, 5 Jul 2001, Manpreet Singh wrote:

> Do we need any support in the eepro100 driver to make use of the D0 to D3
> low power states of the 82559ER chip ?

My driver already uses the D2 power status while the interface is
deactivated.

> The Intel spec is confusing on this.

This is pretty much standard behavior, so the datasheet (which one are
you using?) might not cover it.

> It is specified that the PME# signal is
> enabled on a wake-up event. But I am not clear on whether the PME#
> automatically triggers the chip into a D0 state ( from a D1 or D2 ) or does
> the driver need to take note of this and change the state of the chip to D0.

No, the chip stays in the same state.  The driver is responsible for
changing the chip's state to active.  The code to do this is in the
pci-scan.o support module that is required with my drivers.

This isn't usually an issue, because suspend-to-memory isn't a common
feature on current systems.

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
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