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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 18F98ECDFB1 for ; Tue, 17 Jul 2018 16:33:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF94A20684 for ; Tue, 17 Jul 2018 16:33:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF94A20684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=nocrew.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729980AbeGQRHD (ORCPT ); Tue, 17 Jul 2018 13:07:03 -0400 Received: from pio-pvt-msa2.bahnhof.se ([79.136.2.41]:40682 "EHLO pio-pvt-msa2.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729620AbeGQRHD (ORCPT ); Tue, 17 Jul 2018 13:07:03 -0400 Received: from localhost (localhost [127.0.0.1]) by pio-pvt-msa2.bahnhof.se (Postfix) with ESMTP id 594D83F428; Tue, 17 Jul 2018 18:33:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at bahnhof.se Received: from pio-pvt-msa2.bahnhof.se ([127.0.0.1]) by localhost (pio-pvt-msa2.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id suxv1dsbpikH; Tue, 17 Jul 2018 18:33:32 +0200 (CEST) Received: from localhost.localdomain (h-155-4-135-114.NA.cust.bahnhof.se [155.4.135.114]) (Authenticated sender: mb547485) by pio-pvt-msa2.bahnhof.se (Postfix) with ESMTPA id 1BB013F32B; Tue, 17 Jul 2018 18:33:31 +0200 (CEST) Date: Tue, 17 Jul 2018 18:33:30 +0200 From: Fredrik Noring To: Christoph Hellwig Cc: Robin Murphy , m.szyprowski@samsung.com, Geoff Levand , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, JuergenUrban@gmx.de Subject: Re: [PATCH] dma-mapping: Relax warnings for per-device areas Message-ID: <20180717163330.GE2342@localhost.localdomain> References: <1f8262d206c6886072d04cc93454f6e3f812bd20.1530623284.git.robin.murphy@arm.com> <20180705193613.GA28905@lst.de> <20180715122826.GB2342@localhost.localdomain> <20180717145725.GA22109@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180717145725.GA22109@lst.de> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, Geoff, [ CC-ing Geoff to give him an opportunity to chime in about the PS3 part. ] > > Here are three other regressions related to the coherent mask WARN_ON_ONCE: > > They are a pretty strong indication that yes, you should really set > the coherent mask if you ever do coherent allocations.. I'm unfortunately unfamiliar with the USB drivers for the PS3. Geoff, what do you think about setting a coherent mask? Christoph, what mask value would you suggest for the PS2 driver? Typical DMA addresses 0-0x200000 are mapped to 0x1c000000-0x1c200000 and is memory managed exclusively by the IOP. Robin indicated that DMA_BIT_MASK(20) or a nonzero but useless value such as 1 are possibly candidates. It seems quite unclear what the coherent mask actually means in this case, doesn't it? Fredrik