From mboxrd@z Thu Jan 1 00:00:00 1970 From: mike@compulab.co.il Subject: Re: smsc911x suspend/resume Date: Sun, 14 Feb 2010 11:01:43 +0200 Message-ID: <20100214090143.GA23498@gentoodev.compulab.local> References: <20100208144951.GF28972@buzzloop.caiaq.de> Reply-To: mike@compulab.co.il Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-arm-kernel-bounces@lists.infradead.org, LAKML , Daniel Mack , Ian.Saturley@smsc.com To: Steve.Glendinning@smsc.com Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: netdev.vger.kernel.org On Thu, Feb 11, 2010 at 06:26:32PM +0000, Steve.Glendinning@smsc.com wrote: > > 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. > > I've checked with the chip architects, no power planes should be > externally > switched off in any suspend mode. The question if they *can* be switched off. With the hardware I have, most of 3.3V supplies are enabled/disabled with the same control. So, to have maximal power saving in the system, I just pull this control to disable 3.3V supplies, VDD33A among them. If smsc9220 can tolerate switching VDD33A during suspend, I can send a patch that allows proper wake-up with such conditions. > Steve