From: Mike Rapoport <mike@compulab.co.il> To: Daniel Mack <daniel@caiaq.de> Cc: Steve Glendinning <steve.glendinning@smsc.com>, netdev@vger.kernel.org, LAKML <linux-arm-kernel@lists.infradead.org> Subject: Re: smsc911x suspend/resume Date: Mon, 08 Feb 2010 17:10:16 +0200 [thread overview] Message-ID: <4B702958.5020806@compulab.co.il> (raw) In-Reply-To: <20100208144951.GF28972@buzzloop.caiaq.de> Daniel Mack wrote: > On Mon, Feb 08, 2010 at 04:42:25PM +0200, Mike Rapoport wrote: >> Daniel Mack wrote: >>> In fact the datasheet doesn't really state that, and the chip seems >>> to expect the power domains to remain switched on during suspend, and >>> all power switching is done internally. Also the table in "7.4 Power >>> Consumption (Device and System Components)" describes it like that. >>> >>> So it all comes down to the question of how low-power you need to be, >>> and whether you need wake-on-lan or not. What's currently implemented is >>> D1, but adding support for D2 should be easy. >> I did some brute force save/restore of smsc9220 registers and it seems >> to wake up now. >> The question now is how to make it in a "generic" way ... >> Thanks for the help anyway :) > > Hmm, be careful about switching off power supplies that aren't supposed > to be switched off while others are still powered. You can easily > destroy hardware with that. Depending on how things are wired up > internally, voltages can leak from one unit block to the other. Maybe > Steve can can give a statement from official SMSC source about whether > it is safe to switch off VDD33A in this case. > > Anyway, from what's written in the datasheet, I wouldn't dare just > blindly doing it. I haven't dig too much in the datasheet, but I cannot remember anything about keeping certain power supplies on during suspend. The only clue is your comment in the driver that states "/* This implementation assumes the devices remains powered on its VDDVARIO * pins during suspend. */" And the platform I have either disables all supplies but VDDVARIO or keeps them all up. Anyway, I'll leave it running sleep/resume/ping cycle overnight to see in the morning what have burned :) > Daniel -- Sincerely yours, Mike.
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From: mike@compulab.co.il (Mike Rapoport) To: linux-arm-kernel@lists.infradead.org Subject: smsc911x suspend/resume Date: Mon, 08 Feb 2010 17:10:16 +0200 [thread overview] Message-ID: <4B702958.5020806@compulab.co.il> (raw) In-Reply-To: <20100208144951.GF28972@buzzloop.caiaq.de> Daniel Mack wrote: > On Mon, Feb 08, 2010 at 04:42:25PM +0200, Mike Rapoport wrote: >> Daniel Mack wrote: >>> In fact the datasheet doesn't really state that, and the chip seems >>> to expect the power domains to remain switched on during suspend, and >>> all power switching is done internally. Also the table in "7.4 Power >>> Consumption (Device and System Components)" describes it like that. >>> >>> So it all comes down to the question of how low-power you need to be, >>> and whether you need wake-on-lan or not. What's currently implemented is >>> D1, but adding support for D2 should be easy. >> I did some brute force save/restore of smsc9220 registers and it seems >> to wake up now. >> The question now is how to make it in a "generic" way ... >> Thanks for the help anyway :) > > Hmm, be careful about switching off power supplies that aren't supposed > to be switched off while others are still powered. You can easily > destroy hardware with that. Depending on how things are wired up > internally, voltages can leak from one unit block to the other. Maybe > Steve can can give a statement from official SMSC source about whether > it is safe to switch off VDD33A in this case. > > Anyway, from what's written in the datasheet, I wouldn't dare just > blindly doing it. I haven't dig too much in the datasheet, but I cannot remember anything about keeping certain power supplies on during suspend. The only clue is your comment in the driver that states "/* This implementation assumes the devices remains powered on its VDDVARIO * pins during suspend. */" And the platform I have either disables all supplies but VDDVARIO or keeps them all up. Anyway, I'll leave it running sleep/resume/ping cycle overnight to see in the morning what have burned :) > Daniel -- Sincerely yours, Mike.
next prev parent reply other threads:[~2010-02-08 15:11 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-02-08 9:42 smsc911x suspend/resume Mike Rapoport 2010-02-08 9:42 ` Mike Rapoport 2010-02-08 10:11 ` Daniel Mack 2010-02-08 10:11 ` Daniel Mack 2010-02-08 11:30 ` Mike Rapoport 2010-02-08 11:30 ` Mike Rapoport 2010-02-08 11:46 ` Daniel Mack 2010-02-08 11:46 ` Daniel Mack 2010-02-08 14:42 ` Mike Rapoport 2010-02-08 14:42 ` Mike Rapoport 2010-02-08 14:49 ` Daniel Mack 2010-02-08 14:49 ` Daniel Mack 2010-02-08 15:10 ` Mike Rapoport [this message] 2010-02-08 15:10 ` Mike Rapoport 2010-02-11 18:26 ` Steve.Glendinning 2010-02-11 18:26 ` Steve.Glendinning at smsc.com 2010-02-14 9:01 ` mike 2010-02-14 9:01 ` mike at compulab.co.il 2010-02-08 11:46 ` Steve.Glendinning 2010-02-08 11:46 ` Steve.Glendinning at smsc.com 2010-02-08 11:53 ` Daniel Mack 2010-02-08 11:53 ` Daniel Mack 2010-02-08 12:27 ` Steve.Glendinning 2010-02-08 12:27 ` Steve.Glendinning at smsc.com 2010-02-08 13:55 ` Mike Rapoport 2010-02-08 13:55 ` Mike Rapoport 2015-03-06 9:16 Ran Shalit
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