Subject: Re: smsc911x suspend/resume

From: Daniel Mack <[email-masked]>
Date: Mon, 8 Feb 2010 12:53:16 +0100

On Mon, Feb 08, 2010 at 11:46:39AM +0000, [email-masked] wrote:
> > Anyway, I have all the supplies except VDDVARIO shut down...
> > And the datasheet is indeed comprehensively describes chip power states
> > but I haven't found there anything about supplies required to stay on
> > during suspend...
> 
> I don't have the code in front of me (I'm travelling today) but IIRC
> the driver doesn't place the LAN9220 in a specific power saving state,
> so as far as the LAN9220 is concerned it's not actually suspended.

It does, I added that awhile back in b6907b0c7. But as I say, this is
currently hard-coded to D1, and if support for D2 is desired, we would
need to make that a platform data option.

> It's hard to do this in a "generic" way: some people expect their link
> to stay up during suspend, some want suspend to completely power down
> the ethernet chip, and some want to use one of several WoL modes. 
> 
> David: What's the "done thing" here for similar non-pci drivers?
> Obviously "doesn't work after suspend" isn't the intended behaviour, so
> there's definitely room for improvement!
> 
> > > Also have a look at the Raumfeld device patches which use exactly this
> > > chip and which can suspend and resume just fine. You'll need to check
> > > out Eric's devel branch for that.
> 
> Daniel: I haven't seen this, do you have a location for the git tree?

git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6.git

See the 'devel' branch. But there's actually nothing exciting in there,
it's just a simple platform support.

Daniel