From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Luethi Subject: Re: [2/3] via-rhine: de-isolate PHY Date: Sun, 8 Aug 2004 23:54:58 +0200 Sender: linux-kernel-owner@vger.kernel.org Message-ID: <20040808215458.GA21994@k3.hellgate.ch> References: <411684D5.8020302@colorfullife.com> <20040808200532.GA19170@k3.hellgate.ch> <41169546.5000308@colorfullife.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, Netdev Return-path: To: Manfred Spraul Content-Disposition: inline In-Reply-To: <41169546.5000308@colorfullife.com> List-Id: netdev.vger.kernel.org On Sun, 08 Aug 2004 23:04:06 +0200, Manfred Spraul wrote: > Roger Luethi wrote: > >>I know that PHYs go into isolate mode if the startup id is wired to 0, > > > >Wouldn't that be s/go/can go/ ? > > > I don't have the MII standard, my knowledge is from the DP83840A specs: > The pin description contains a section about the phy ids: > During power up five pins are latched to determine the initial phy address. > Then the following sentence in bold: "An address selection of all zeros > (00000) will result in a PHY isolation condition". I suppose all PHYs do that. Even if they don't, though, I should be safe as long as I de-isolate unconditionally (instead of testing for phy_id==0). > I've reread the DP specs and I now think that your current patch is > sufficient: > The isolate state is independant from the phy address - a non-zero phy > can be in isolate mode and the phy zero can be non-isolated. The phy id Stands to reason. A PHY that can't get out of isolation wouldn't be very useful. > If this is really true then handling phy 0 is trivial: > First scan 1-31. If nothing found: try 0. If a phy is found: clear the > isolate bit and then use phy 0. Makes sense. The Rhine is actually pretty neat in that regard, I've been able to drop the PHY scanning entirely. Roger