From mboxrd@z Thu Jan 1 00:00:00 1970 From: mike@compulab.co.il (Mike Rapoport) Date: Mon, 08 Feb 2010 15:55:59 +0200 Subject: smsc911x suspend/resume In-Reply-To: References: Message-ID: <4B7017EF.4080909@compulab.co.il> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Steve.Glendinning at smsc.com wrote: > Hi Mike, > >>>> I'm trying to make suspend/resume work on OMAP3-based system and I'm >>>> encountering issues with resume of SMSC 9220 chip. >>>> After resume the interface is unusable unless I do 'ifconfig eth0 > down' >>>> and 'ifconfig eth0 up'. >>>> I would expect that 'ping ' would work right after resume >>>> without need to bring the interface down and up, but probably I miss >>>> something. >>>> Any help would be appreciated. >>> What happens to your supply voltages when going to suspend? When I >>> implemented the code for the smsc driver, I could only test scenarios >>> where AVDD remains stable during suspend. So the driver might need > some >>> tweaks if that assumption is not true in your case. The SMSC datasheet >>> is quite comprehensive about this topic IIRC. >> By AVDD you mean VDD33A? >> 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'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. Indeed a "generic" implementation may be tough task... Probably we can add some platform_data flags for suspend modes and use them to decide what low power mode should be selected? > 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? > > Thanks, > Steve -- Sincerely yours, Mike.