From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 84188C28CC5 for ; Sat, 8 Jun 2019 07:25:34 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D777A208E3 for ; Sat, 8 Jun 2019 07:25:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D777A208E3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45LWBz0Y1czDr1m for ; Sat, 8 Jun 2019 17:25:31 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=newverein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from newverein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45LW965tV1zDqn4 for ; Sat, 8 Jun 2019 17:23:52 +1000 (AEST) Received: by newverein.lst.de (Postfix, from userid 2407) id 7E63E68B02; Sat, 8 Jun 2019 09:23:22 +0200 (CEST) Date: Sat, 8 Jun 2019 09:23:22 +0200 From: Christoph Hellwig To: Benjamin Herrenschmidt Subject: Re: [BISECTED REGRESSION] b43legacy broken on G4 PowerBook Message-ID: <20190608072322.GA18896@lst.de> References: <20190605225059.GA9953@darkstar.musicnaut.iki.fi> <73da300c-871c-77ac-8a3a-deac226743ef@lwfinger.net> <7697a9d10777b28ae79fdffdde6d0985555f6310.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7697a9d10777b28ae79fdffdde6d0985555f6310.camel@kernel.crashing.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Aaro Koskinen , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Zigotzky , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig , Larry Finger Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat, Jun 08, 2019 at 02:21:23PM +1000, Benjamin Herrenschmidt wrote: > > > Please try the attached patch. I'm not really pleased with it and I will > > continue to determine why the fallback to a 30-bit mask fails, but at least this > > one works for me. > > Your patch only makes sense if the device is indeed capable of > addressing 31-bits. > > So either the driver is buggy and asks for a too small mask in which > case your patch is ok, or it's not and you're just going to cause all > sort of interesting random problems including possible memory > corruption. Well, my patches changes ZONE_DMA to be 30-bits instead of 31, and thus should allow requesting a 30-bit mask to succeed.