From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: update: RE: nap/dfs on 7448 From: Benjamin Herrenschmidt To: "Leisner, Martin" In-Reply-To: <556445368AFA1C438794ABDA8901891C07C113CC@USA0300MS03.na.xerox.net> References: <556445368AFA1C438794ABDA8901891C0738E1E8@USA0300MS03.na.xerox.net> <1191304917.6310.99.camel@pasglop> <556445368AFA1C438794ABDA8901891C07C113CC@USA0300MS03.na.xerox.net> Content-Type: text/plain Date: Fri, 28 Dec 2007 16:19:45 +1100 Message-Id: <1198819185.7209.18.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev Reply-To: benh@kernel.crashing.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2007-12-27 at 17:37 -0500, Leisner, Martin wrote: > Turns out the Tundra TSI109 has various "problems" trying > to nap -- its not a 7448 issue... > > We're working with tundra to get a workaround (in software, they > won't respin the part). It seems DMA while napping is an issue, we > have to turn off the tsi109 ethernet queues before entering nap mode... > > If anyone needs this work, let me know (it will be covered under GPL). This looks like yet another f*cked up bridge ... I wonder if we'll ever get a half decent working northbridge for those processors... Unfortunately, it looks like the market for those is limited to junk from vendor A and shit from vendor B... Is the problem limited to the TSI internal ethernet or it happens with any DMA ? Looks to me like turning off DMA in NAP mode basically makes NAP mode unuseable, perdiod. You can't start loosing packets because your processor is idle. So no power saving, and let's eat the watts since they won't respin the part. Great ! Ben.